Barrett Business Services (BBSI) 10-K 16 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Mar. 02, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	BBSI
Entity Registrant Name	BARRETT BUSINESS SERVICES INC
Entity Central Index Key	902791
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		7,137,791
Entity Public Float			$330,349,417

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$11,544	$93,557
Marketable securities	29,957	19,787
Trade accounts receivable, net	102,627	85,586
Income taxes receivable	11,421	0
Prepaid expenses and other	3,813	3,026
Restricted marketable securities and workers' compensation deposits	3,776	0
Deferred income taxes	15,791	8,929
Total current assets	178,929	210,885
Marketable securities	20,930	5,909
Property, equipment and software, net	22,675	20,549
Restricted certificates of deposit	114,335	12,789
Restricted marketable securities and workers' compensation deposits	58,533	11,205
Other assets	1,881	1,864
Workers' compensation receivables for insured losses and recoveries	3,425	2,301
Goodwill	47,820	47,820
Total assets	448,528	313,322
Current liabilities:
Current portion of long-term debt	25,220	220
Accounts payable	2,719	3,252
Accrued payroll, payroll taxes and related benefits	120,133	92,516
Income taxes payable	0	1,236
Other accrued liabilities	1,917	313
Workers' compensation claims liabilities	54,049	35,841
Safety incentives liability	14,232	13,086
Total current liabilities	218,270	146,464
Long-term workers' compensation claims liabilities	161,933	76,603
Long-term debt	19,833	5,053
Deferred income taxes	8,159	10,787
Customer deposits and other long-term liabilities	1,675	1,862
Commitments and contingencies
Stockholders' equity:
Common stock, $.01 par value; 20,500 shares authorized, 7,126 and 7,165 shares issued and outstanding	71	72
Additional paid-in capital	4,410	5,781
Accumulated other comprehensive loss	-23	-26
Retained earnings	34,200	66,726
Total stockholders' equity	38,658	72,553
Total liabilities and stockholders' equity	$448,528	$313,322

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Per Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	20,500	20,500
Common stock, shares issued	7,126	7,165
Common stock, shares outstanding	7,126	7,165

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Professional employer service fees	$470,351	$388,963	$276,004
Staffing services	165,833	143,881	126,648
Total revenues	636,184	532,844	402,652
Cost of revenues:
Direct payroll costs	126,399	108,800	95,128
Payroll taxes and benefits	266,844	228,903	169,724
Workers' compensation	212,524	108,617	71,086
Total cost of revenues	605,767	446,320	335,938
Gross margin	30,417	86,524	66,714
Selling, general and administrative expenses	73,821	60,061	46,450
Depreciation and amortization	2,506	2,037	1,477
(Loss) income from operations	-45,910	24,426	18,787
Other income (expense):
Investment income	594	723	776
Interest expense	-173	-238	-76
Other	152	-9	-28
Other income	573	476	672
(Loss) income before income taxes	-45,337	24,902	19,459
(Benefit from) provision for income taxes	-18,253	7,010	6,328
Net (loss) income	($27,084)	$17,892	$13,131
Basic (loss) earnings per share	($3.78)	$2.52	$1.70
Weighted average number of basic shares outstanding	7,160	7,105	7,723
Diluted (loss) earnings per share	($3.78)	$2.42	$1.67
Weighted average number of diluted shares outstanding	7,160	7,397	7,863
Cash dividends per common share	$0.76	$0.57	$0.46

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive (Loss) Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net (loss) income	($27,084)	$17,892	$13,131
Unrealized gains (losses) on marketable securities, net of tax	3	-49	57
Comprehensive (loss) income	($27,081)	$17,843	$13,188

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive (Loss) Income (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Unrealized gains (losses) on marketable securities, tax	$3	($31)	$36

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Retained Earnings [Member]
In Thousands, except Share data
Beginning balance at Dec. 31, 2011	$101,655	$99	$20,943	($34)	$80,647
Beginning balance, shares at Dec. 31, 2011		9,871,000
Common stock issued on exercise of options	1,845	1	1,844	0	0
Common stock issued on exercise of options, shares	131,997	132,000
Share based compensation expense, net of tax	695	0	695	0	0
Share based compensation expense, net of tax, shares		0
Excess tax benefits from share-based compensation	295	0	295	0	0
Company repurchase of common stock	-60,232	-30	-22,864	0	-37,338
Company repurchase of common stock, shares	0	-2,986,000
Cash dividends on common stock	-3,550	0	0	0	-3,550
Unrealized holding gains (losses) on marketable securities, net of tax	57	0	0	57	0
Net (loss) income	13,131	0	0	0	13,131
Ending balance at Dec. 31, 2012	53,896	70	913	23	52,890
Ending balance, shares at Dec. 31, 2012		7,017,000
Common stock issued on exercise of options and vesting of restricted stock units	1,860	2	1,858	0	0
Common stock issued on exercise of options and vesting of restricted stock units, shares		148,000
Common stock repurchased on vesting of restricted stock units	-89	0	-89	0	0
Common stock issued on exercise of options, shares	138,298
Common stock repurchased on vesting of restricted stock units, shares		0
Share based compensation expense, net of tax	1,016	0	1,016	0	0
Share based compensation expense, net of tax, shares		0
Excess tax benefits from share-based compensation	2,083	0	2,083	0	0
Company repurchase of common stock, shares	0
Cash dividends on common stock	-4,056	0	0	0	-4,056
Unrealized holding gains (losses) on marketable securities, net of tax	-49	0	0	-49	0
Net (loss) income	17,892	0	0	0	17,892
Ending balance at Dec. 31, 2013	72,553	72	5,781	-26	66,726
Ending balance, shares at Dec. 31, 2013		7,165,000
Common stock issued on exercise of options and vesting of restricted stock units	434	0	434	0	0
Common stock issued on exercise of options and vesting of restricted stock units, shares		56,000
Common stock repurchased on vesting of restricted stock units	-407	0	-407	0	0
Common stock issued on exercise of options, shares	32,866
Common stock repurchased on vesting of restricted stock units, shares		-8,000
Share based compensation expense, net of tax	1,699	0	1,699	0	0
Share based compensation expense, net of tax, shares		0
Excess tax benefits from share-based compensation	578	0	578	0	0
Company repurchase of common stock	-3,676	-1	-3,675	0	0
Company repurchase of common stock, shares	-87,200	-87,000
Cash dividends on common stock	-5,442	0	0	0	-5,442
Unrealized holding gains (losses) on marketable securities, net of tax	3	0	0	3	0
Net (loss) income	-27,084	0	0	0	-27,084
Ending balance at Dec. 31, 2014	$38,658	$71	$4,410	($23)	$34,200
Ending balance, shares at Dec. 31, 2014		7,126,000

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net (loss) income	($27,084)	$17,892	$13,131
Reconciliations of net (loss) income to net cash provided by operating activities:
Depreciation and amortization	2,506	2,037	1,477
Losses (gains) recognized on marketable securities	3	-1	-4
Gain recognized on sale and leaseback	0	-60	-122
Deferred income taxes	-9,487	-632	301
Share based compensation	1,699	1,016	695
Excess tax benefit from share-based compensation	-578	-2,083	-295
Changes in certain assets and liabilities:
Trade accounts receivable, net	-17,041	-21,665	-17,401
Income taxes receivable	-11,421	0	4,133
Prepaid expenses and other	-387	1,828	1,043
Accounts payable	-533	1,257	356
Accrued payroll, payroll taxes and related benefits	27,617	22,948	17,228
Other accrued liabilities	1,604	7	6
Income taxes payable	-658	3,047	567
Workers' compensation claims liabilities	103,538	41,880	20,663
Safety incentives liability	1,146	3,244	3,521
Customer deposits, long-term liabilities and other assets, net	-1,328	-519	358
Net cash provided by operating activities	69,596	70,196	45,657
Cash flows from investing activities:
Purchase of property and equipment	-4,632	-4,097	-3,712
Proceeds from sales and maturities of marketable securities	13,241	60,850	39,190
Purchase of marketable securities	-38,434	-59,917	-33,539
Proceeds from maturities of restricted certificates of deposit	0	63,944	0
Purchase of restricted certificates of deposit	-101,546	-76,733	0
Proceeds from maturities of restricted marketable securities	10,524	9,918	10,796
Purchase of restricted marketable securities	-61,628	-11,397	-10,599
Net cash (used in) provided by investing activities	-182,475	-17,432	2,136
Cash flows from financing activities:
Proceeds from credit-line borrowings	6,242	132,664	50,229
Payments on credit-line borrowings	-6,242	-137,196	-45,697
Proceeds from the issuance of long-term debt	40,000	0	5,512
Commitment fee from the issuance of long-term debt	-400	0	0
Payments on long-term debt	-220	-220	-19
Repurchase of common stock	-3,676	0	-25,432
Common stock repurchased on vesting of restricted stock units	-407	-89	0
Redemption of mandatorily redeemable preferred stock	0	0	-34,800
Dividends paid	-5,443	-4,056	-3,550
Proceeds from the exercise of stock options and vesting of restricted stock units	434	1,860	1,845
Excess tax benefit from share-based compensation	578	2,083	295
Net cash provided by (used in) financing activities	30,866	-4,954	-51,617
Net (decrease) increase in cash and cash equivalents	-82,013	47,810	-3,824
Cash and cash equivalents, beginning of year	93,557	45,747	49,571
Cash and cash equivalents, end of year	11,544	93,557	45,747
Mandatorily redeemable preferred stock [Member]
Supplemental schedule of noncash financing activities:
Issuance of mandatorily redeemable preferred stock	$0	$0	$34,800

Summary_of_Operations_and_Sign

Summary of Operations and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Operations and Significant Accounting Policies	1	Summary of Operations and Significant Accounting Policies
	Nature of operations
	Barrett Business Services, Inc. (“BBSI”, the “Company”), is a leading provider of business management solutions for small-and mid-sized companies. The Company has developed a management platform that integrates a knowledge-based approach from the management consulting industry with tools from the human resource outsourcing industry. This platform, through the effective leveraging of human capital, assists our business owner clients in more effectively running their business. We believe this platform, delivered through a decentralized organizational structure, differentiates BBSI from our competitors. The Company operates through a network of branch offices throughout California, Oregon, Washington, Idaho, Arizona, Nevada, Utah, Colorado, Maryland, Delaware and North Carolina. Approximately 77%, 74% and 69%, respectively, of our revenue during 2014, 2013 and 2012 was attributable to our California operations. BBSI was incorporated in Maryland in 1965.
	The Company operates a wholly owned captive insurance company, Associated Insurance Company for Excess (“AICE”). AICE is a fully licensed captive insurance company holding a certificate of authority from the Arizona Department of Insurance. The purpose of AICE is twofold: (1) to provide access to more competitive and cost effective insurance markets and (2) to provide additional flexibility in cost effective risk management. The captive handles the Company’s workers’ compensation claims occurring on or after January 1, 2007. AICE provides excess workers’ compensation coverage from $1.0 million up to $5.0 million per occurrence in the states of California, Oregon, Delaware and Washington. AICE also provides general liability insurance coverage for BBSI.
	The Company also operates a wholly owned insurance company, Ecole Insurance Company (“Ecole”). Ecole is a fully licensed insurance company holding a certificate of authority from the Arizona Department of Insurance. Ecole provides workers’ compensation coverage to the Company’s employees working in Arizona beginning with claims occurring on or after March 1, 2010. The restricted capital used to capitalize the insurance company was approximately $6.1 million and is included in restricted marketable securities and workers’ compensation deposits in our consolidated balance sheets.
	Principles of consolidation
	The accompanying financial statements are prepared on a consolidated basis. All significant intercompany account balances and transactions between BBSI, AICE, Ecole and BBS I, LLC, the aircraft subsidiary which owns an aircraft for management’s operational travel needs, have been eliminated in consolidation.
	Reportable Segment
	The Company has one principal operating and reporting segment. The chief operating decision maker (currently our Chief Executive Officer) regularly reviews the financial information of our business at a consolidated level in deciding how to allocate resources and assessing performance.
	Revenue recognition
	We recognize revenue as services are rendered by our workforce. Professional employer (PEO) services are normally used by organizations to satisfy ongoing needs related to the management of human capital and are governed by the terms of a client services agreement with a minimum term of one year, which cover all employees at a particular work site. Our client services agreements are renewable on an annual basis and typically require 30 days’ written notice to cancel or terminate the contract by either party. Our client services agreements provide for immediate termination upon any default of the client regardless of when notice is given. We report PEO revenues on a net basis because we are not the primary obligor for the services provided by our clients to their customers pursuant to our client services agreements. Consequently, these service fee revenues represent the gross margin generated from our professional employer services after deducting the amounts invoiced to our clients for direct payroll expenses such as salaries, wages, health insurance, employee out-of-pocket expenses incurred incidental to employment, and safety incentives. These amounts are also excluded from cost of revenues. Professional Employer service fees also include amounts invoiced to our clients for employer payroll-related taxes and workers’ compensation coverage. Staffing services are engaged by customers to meet short-term and long-term personnel needs.
	Cost of revenues
	Our cost of revenues for PEO services includes employer payroll related taxes and workers’ compensation. Our cost of revenues for staffing services is comprised of direct payroll costs, employer payroll related taxes, employee benefits, and workers’ compensation. Direct payroll costs represent the gross payroll earned by staffing services employees based on salary or hourly wages. Payroll taxes and employee benefits consist of the employer’s portion of Social Security and Medicare taxes, federal and state unemployment taxes, and staffing services employee reimbursements for materials, supplies and other expenses, which are paid by our customer. Workers’ compensation costs consist primarily of the costs associated with our self-insured workers’ compensation program, such as claims reserves, claims administration fees, legal fees, state administrative agency fees and excess insurance premiums for catastrophic injuries.
	We maintain separate workers’ compensation insurance policies for employees working in states where the Company is not self-insured. Safety incentives represent cash incentives paid to certain client companies engaged in a client services agreement, for maintaining safe-work practices in order to minimize workplace injuries. The incentive is based on a percentage of annual payroll and is paid annually to clients who meet predetermined workers’ compensation claims cost objectives.
	Cash and cash equivalents
	We consider non-restricted short-term investments, which are highly liquid, readily convertible into cash, and have original maturities of less than three months, to be cash equivalents for purposes of the consolidated statements of cash flows. A substantial portion of the Company’s cash and cash equivalents is invested in tax-exempt money market funds managed by the Company’s principal bank. The Company maintains cash balances in bank accounts that normally exceed FDIC insured limits. The Company has not experienced any losses related to its cash concentration.
	Marketable securities
	As of December 31, 2014, the Company’s marketable securities consisted of tax-exempt municipal securities, U.S. Treasuries, variable rate demand notes (VRDN) and corporate bonds. We determine the appropriate classification for certain investments in debt securities, and classify our marketable securities as trading or available-for-sale. The Company classifies municipal securities, U.S. Treasuries, VRDN, and corporate bonds as available for sale; they are reported at fair value with unrealized gains and losses, net of taxes, shown as a component of accumulated other comprehensive (loss) income in stockholders’ equity. Management considers available evidence in evaluating potential impairment of investments, including the duration and extent to which fair value is less than cost and the Company’s ability and intent to hold the investments. In the event a loss is determined to be other-than-temporary, the loss will be recognized in the consolidated statements of operations.
	Restricted marketable securities
	At December 31, 2014 and 2013, restricted marketable securities consisted of money market funds held in trust, U.S. Treasures, municipal debt instruments, and corporate debt instruments with maturities generally from 180 days to two years (see Note 3, Note 4 and Note 6). At December 31, 2014 and 2013, the approximate fair value of restricted marketable securities equaled their approximate amortized cost. Restricted marketable securities have been categorized as available-for-sale; they are reported at fair value with unrealized gains and losses, net of taxes, shown as a component of accumulated other comprehensive (loss) income in stockholders’ equity. Realized gains and losses on sales of restricted marketable securities are included in other income (expense) on our consolidated statements of operations.
	Allowance for doubtful accounts
	We must make estimates of the collectability of our accounts receivable for services provided to our customers. Our management analyzes historical bad debts, customer concentrations, customer credit-worthiness, current economic conditions, and changes in customers’ payment trends when evaluating the adequacy of the allowance for doubtful accounts. If the financial condition of our customers deteriorates, resulting in an impairment of their ability to make payments, additional allowances may be required.
	Our allowance for doubtful accounts activity is summarized as follows (in thousands):
			2014			2013			2012
	Balance at January 1,
	Allowance for doubtful accounts		$	242		$	381		$	452
	Charges to expense			103			300			195
	Write-offs of uncollectible accounts, net of recoveries			(54	)		(439	)		(266	)
	Balance at December 31,
	Allowance for doubtful accounts		$	291		$	242		$	381
	Income taxes
	Our income taxes are accounted for using an asset and liability approach. This requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statement and tax basis of assets and liabilities at the applicable tax rates. A valuation allowance is recorded against deferred tax assets if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The factors used to assess the likelihood of realization include the Company’s forecast of the reversal of temporary differences, future taxable income and available tax planning strategies that could be implemented to realize the net deferred tax assets. Failure to achieve forecasted taxable income in applicable tax jurisdictions could affect the ultimate realization of deferred tax assets and could result in an increase in the Company’s effective tax rate on future earnings.
	The determination of our provision for income taxes requires significant judgment, the use of estimates, and the interpretation and application of complex tax laws. Significant judgment is required in assessing the timing and amounts of deductible and taxable items and the probability of sustaining uncertain tax positions. The Company recognizes the tax benefit from uncertain tax positions if it is more likely than not that the tax positions will be sustained on examination by the tax authorities, based on the technical merits of the position. The tax benefit is measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. As facts and circumstances change, we reassess these probabilities and would record any changes in the consolidated financial statements as appropriate. The Company recognizes interest and penalties related to unrecognized tax benefits in income tax expense.
	Business combinations
	We account for business combinations using the acquisition method of accounting. Transaction costs incurred in connection with a business combination are expensed as incurred. Changes in deferred tax asset valuation allowances and acquired income tax uncertainties after the measurement period are recognized in earnings.
	Goodwill and intangible assets
	Goodwill is recorded as the difference, if any, between the aggregate consideration paid for a business combination and the fair value of the net assets acquired. Goodwill is not amortized, but is evaluated for impairment annually, or more frequently if indicators of impairment are present or changes in circumstances suggest that impairment may exist. The Company has one reporting unit and evaluates the carrying value of goodwill annually at December 31. No impairment has been recognized in the periods presented.
	Our intangible assets with definite lives are amortized on a straight-line basis over their estimated economic useful lives.
	Property, equipment and software
	Property, equipment and software are stated at cost. Expenditures for maintenance and repairs are charged to operating expense as incurred and expenditures for additions and improvements are capitalized. The cost of assets sold or otherwise disposed of and the related accumulated depreciation are eliminated from the accounts, and any resulting gain or loss is reflected in the consolidated statements of operations.
	Depreciation of property, equipment and software is calculated using either straight-line or accelerated methods over estimated useful lives of the related assets or lease terms, as follows:
			Years
	Buildings		39
	Office furniture and fixtures		7
	Computer hardware and software		10-Mar
	Aircraft		20
	Leasehold improvements		Shorter of lease term or estimated useful life
	Impairment of long-lived assets
	Long-lived assets, such as property, equipment and software and acquired intangibles, subject to amortization, are reviewed for impairment annually, or whenever events or changes in circumstances indicate that the remaining estimated useful life may warrant revision or that the carrying amount of an asset may not be recoverable. Some of the events or changes in circumstances that would trigger an impairment review include, but are not limited to, significant under-performance relative to expected and/or historical results (such as two years of significant sales declines or two years of significant negative operating cash flows), significant negative industry or economic trends, or knowledge of transactions involving the sale of similar property at amounts below the carrying value.
	Assets are grouped for recognition and measurement of impairment at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets. If the carrying amount of an asset group exceeds the estimated, undiscounted future cash flows expected to be generated by the asset, then an impairment charge is recognized to the extent the carrying amount exceeds the asset’s fair value. In determining fair value, management considers current results, trends, future prospects, and other economic factors.
	Workers’ compensation claims liabilities
	The estimated liability for unsettled workers’ compensation claims represents an evaluation of information provided by our internal claims adjusters and our third-party administrators for workers’ compensation claims, coupled with an actuarial estimate of future cost development of reported claims and incurred but not reported claims (together, IBNR) provided by the Company’s independent actuary. Included in the claims liabilities are case reserve estimates for reported losses, plus additional amounts for estimated future development of reported claims and incurred but not reported claims as well as estimates for unallocated loss adjustment expenses, including legal costs. These estimates are continually reviewed and adjustments to liabilities are reflected in current operating results as they become known.
	The Company’s independent actuary provides management with an estimate of the current portion and long-term portion of our total workers’ compensation claims. The current portion represents the best estimate of 2014 and prior year claims expected to be paid out in 2015. The Company will also pay out a portion of the 2015 claims during 2015.
	Our workers’ compensation claims liabilities do not represent an exact calculation of liability, but instead represent management’s best estimate, generally utilizing actuarial expertise and projection techniques, at a given accounting date. The process of estimating unpaid claims and claim adjustment expense involves a high degree of judgment and is subject to a number of variables. These variables can be affected by both internal and external events such as changes in claims handling and reserve estimation procedures, changes in individuals involved in the reserve estimation process, inflation, legal trends and legislative changes.
	We use informed judgment throughout the process, derived from individual experiences and expertise applied to multiple sets of data and analysis. We consider all significant facts and circumstances known at the time loss reserves are established and as new facts and circumstances become known. Due to the inherent uncertainty underlying loss reserve estimates including, but not limited to, the future settlement environment, final resolution of our estimated liability for our workers’ compensation claims will likely be higher or lower than the related loss reserves at the reporting date. Therefore, actual paid losses, as specific claims are settled in the future, may be materially different in amount from our current loss reserves.
	A basic premise in most actuarial analyses is that historical data and past patterns demonstrated in the incurred and paid historical data form a reasonable basis upon which to project future outcomes, absent a material change. To the extent a material change affecting the ultimate claim liability is known, such change is quantified to the extent possible through an analysis of internal Company data and, if available and when appropriate, external data. Significant structural changes to the available data can materially impact the reserve estimation process. Actuaries exercise a considerable degree of judgment in the evaluation of these factors in their analysis of reserves. The application of actuarial judgment is unavoidable when faced with material uncertainty. Different actuaries may choose different assumptions when faced with such uncertainty, based on their individual backgrounds, professional experiences and the context in which they are reviewing the reserves. Hence, the estimates selected by different actuaries may differ materially from each other.
	Safety incentives liability
	Safety incentives represent cash incentives paid to certain PEO client companies for maintaining safe-work practices in order to minimize workplace injuries. The incentive is based on a percentage of annual payroll and is paid annually to customers who meet predetermined workers’ compensation claims cost objectives. Safety incentive payments are made only after closure of all workers’ compensation claims incurred during the customer’s contract period. The liability is estimated and accrued each month based upon contract year-to-date payroll and the then-current amount of the customer’s estimated workers’ compensation claims reserves as established by us and our third party administrator and the expected payout as determined by historical incentive payment trends. Safety incentive expense is netted against PEO services revenue in our consolidated statements of operations.
	Customer deposits
	We require deposits from certain PEO customers to cover a portion of our accounts receivable due from such customers in the event of default of payment.
	Comprehensive (loss) income
	Comprehensive (loss) income includes all changes in equity during a period except those that resulted from investments by or distributions to the Company’s stockholders.
	Other comprehensive (loss) income refers to revenues, expenses, gains and losses that under generally accepted accounting principles are included in comprehensive (loss) income, but excluded from net (loss) income as these amounts are recorded directly as an adjustment to stockholders’ equity. Our other comprehensive (loss) income is comprised of unrealized holding gains and losses on our available for sale marketable securities.
	Statements of cash flows
Interest paid during 2014, 2013 and 2012 did not materially differ from interest expense.
Income taxes paid by the Company in 2014, 2013 and 2012 totaled $3.3 million, $9.0 million and $3.3 million, respectively.
Basic and diluted earnings per share
Basic earnings per share are computed based on the weighted average number of common shares outstanding for each year using the treasury method. Diluted earnings per share reflect the potential effects of the exercise of outstanding stock options. Basic and diluted shares outstanding are summarized as follows (in thousands):
		Year Ended
		December 31,
		2014			2013			2012
Weighted average number of basic shares outstanding			7,160			7,105			7,723
Effect of dilutive securities			0			292			140
Weighted average number of diluted shares outstanding			7,160			7,397			7,863
As a result of the net loss for the year ended December 31, 2014, 227,000 potential common shares have been excluded from the calculation of diluted loss per share because their effect would be anti-dilutive.
Reclassifications
Certain prior year amounts have been reclassified to conform to the 2014 presentation. Such reclassifications had no impact on the Company’s financial condition, operating results, cash flows, working capital or stockholder’s equity.
Accounting estimates
The preparation of our consolidated financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Estimates are used for carrying values of marketable securities, allowance for doubtful accounts, deferred income taxes, carrying values for goodwill and property and equipment, accrued workers’ compensation liabilities and safety incentive liabilities. Actual results may or may not differ from such estimates.
Recent Accounting Pronouncements
In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09 Revenue from Contracts with Customers, which will supersede nearly all existing revenue recognition guidance under U.S. GAAP. The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The new standard is effective for the Company on January 1, 2017. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method or determined the effect of the standard on its ongoing financial reporting.
In September 2014, the FASB issued new accounting guidance on disclosure of uncertainties about an entity’s ability to continue as a going concern. The new guidance requires an entity’s management to evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued, and if so, disclose that fact. Management is also required to evaluate and disclose whether its plans alleviate that doubt. The guidance is effective for us in 2017 and will be applicable to both annual and interim reporting periods. We do not expect the adoption of this guidance to have an impact on our consolidated financial statements.

Stock_Repurchase

Stock Repurchase	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Stock Repurchase	2	Stock Repurchase
	Effective March 28, 2012, the Company repurchased 2,485,929 shares of the Company’s common stock held by the Estate of William W. Sherertz and 500,000 common shares held by Nancy Sherertz. Mr. Sherertz, a founder and former president and CEO of the Company, died January 20, 2011. Nancy Sherertz is also a founder of the Company. The common shares were repurchased at a price of $20 per share, representing total consideration of $59.7 million. The Company used a combination of $24.9 million in cash and issued 34,800 shares of Series A Nonconvertible, Non-Voting Redeemable Preferred Stock with a liquidation preference of $1,000 per share. Additionally, the Company incurred professional and legal fees totaling $514,000 related to the transaction.
	Effective September 21, 2012, the Company redeemed all of the outstanding shares of its Series A Nonconvertible, Non-Voting Redeemable Preferred Stock for $34.8 million using a combination of cash on hand and availability under a new revolving credit facility provided by its principal bank. By redeeming the preferred stock within six months of issuance, the Company avoided having to pay a 5% semi-annual dividend of approximately $870,000 due September 28, 2012.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments and Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments and Concentration of Credit Risk	3	Fair Value of Financial Instruments and Concentration of Credit Risk
	All of our financial instruments are recognized in our consolidated balance sheet. Carrying values approximate fair value of most financial assets and liabilities. The fair value of restricted marketable securities consisting primarily of certificates of deposits, money market funds, municipal bonds, U.S. treasury bills and corporate bonds is recorded at amortized cost, which approximates fair value for similar instruments. The interest rates on our restricted marketable security investments approximate current market rates for these types of investments; therefore, the recorded value of the restricted marketable securities approximates fair value.
	Financial instruments that potentially subject us to concentration of credit risk consist primarily of temporary cash investments, marketable securities, restricted marketable securities and trade accounts receivable. We limit investment of temporary cash investments and marketable securities to financial institutions with high credit ratings, corporate bonds and to investments in governmental debt instruments. Credit risk on trade receivables is minimized as a result of the large and diverse nature of our customer base.
	At December 31, 2014, we had significant concentrations of credit risk as follows:
		•	Marketable securities—$137.6 million, at fair value, in certificates of deposit.
		•	Marketable securities—$50.1 million, at fair value, in money market funds.
		•	Marketable securities—$21.7 million, at fair value, in VRDN.
		•	Marketable securities—$8.2 million, at fair value, in municipal bonds.
		•	Marketable securities—$5.7 million, at fair value, in corporate bonds.

Fair_Value_Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurement	4	Fair Value Measurement
	Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.
	Factors used in determining the fair value of our financial assets and liabilities are summarized into three broad categories:
		•		Level 1—quoted prices in active markets for identical securities;
		•		Level 2—other significant observable inputs, including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.; and
		•		Level 3—significant unobservable inputs, including our own assumptions in determining fair value.
	The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.
	In determining the fair value of our financial assets, the Company predominately uses the market approach. In determining the fair value of all its certificates of deposit, money market funds, U.S. treasuries, municipal bonds, corporate bonds, and variable rate demand notes classified as Level 2, the Company utilizes the non-binding quotes provided by our three investment brokers. We receive one non-binding broker quote for each financial asset as of the balance sheet date. To value the Level 2 assets, our investment brokers use proprietary multi-dimensional pricing models that include a variety of inputs, including quoted prices for identical or similar assets in active markets, quoted prices for identical or similar assets in markets that are not active, interest rates and yield curves observable at commonly quoted intervals, volatilities, prepayment speeds, loss severities, credit risks and default rates that are observable at commonly quoted intervals. There were no assets or liabilities where Level 3 valuation techniques were used and there were no assets and liabilities measured at fair value on a non-recurring basis.
	Marketable securities consist of the following (in thousands):
			December 31, 2014							December 31, 2013							Fair
																	Value
			Cost		Gross			Recorded		Cost		Gross			Recorded		Category
					Unrealized			Basis				Unrealized			Basis
					Gains							(Losses)
					(Losses)
	Current:
	Available-for-sale:
	VRDN		$	21,670	$	0		$	21,670	$	10,000	$	0		$	10,000		2
	Certificates of deposit			8,330		(43	)		8,287		0		0			0		2
	Corporate bonds			0		0			0		9,800		(13	)		9,787		2
			$	30,000	$	(43	)	$	29,957	$	19,800	$	(13	)	$	19,787
	Long term:
	Available-for-sale:
	Municipal bonds		$	3,843	$	7		$	3,850	$	4,074	$	(17	)	$	4,057		2
	Corporate bonds			2,153		(3	)		2,150		1,879		(27	)		1,852		2
	Certificates of deposit			14,944		(14	)		14,930		0		0			0		2
			$	20,940	$	(10	)	$	20,930	$	5,953	$	(44	)	$	5,909
	The Company’s restricted marketable securities component of restricted marketable securities and workers’ compensation deposits consists of the following (in thousands):
			December 31, 2014							December 31, 2013							Fair
																	Value
			Cost		Gross			Recorded		Cost		Gross			Recorded		Category
					Unrealized			Basis				Unrealized			Basis
					Gains							Gains
					(Losses)
	Current:
	Available-for-sale:
	Money market funds held in trust		$	3,776	$	0		$	3,776	$	0	$	0		$	0		2
			$	3,776	$	0		$	3,776	$	0	$	0		$	0
	Long term:
	Available-for-sale:
	Money market funds held in trust		$	46,310	$	0		$	46,310	$	0	$	0		$	0		2
	Municipal bonds			4,352		21			4,373		4,742		10			4,752		2
	Corporate bonds			3,540		(3	)		3,537		2,849		5			2,854		2
	U.S. treasuries			3,963		0			3,963		2,787		0			2,787		1
			$	58,165	$	18		$	58,183	$	10,378	$	15		$	10,393
	The Company’s long term restricted certificates of deposit are summarized as follows (in thousands):
			December 31, 2014							December 31, 2013
			Cost		Gross			Recorded		Cost		Gross			Recorded		Fair
					Unrealized			Basis				Unrealized			Basis		Value
					Gains							Gains					Category
	Restricted certificates of deposit		$	114,335	$	0		$	114,335	$	12,789	$	0		$	12,789		2

Property_Equipment_and_Softwar

Property, Equipment and Software	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property, Equipment and Software	5	Property, Equipment and Software
	Property, equipment and software consist of the following (in thousands):
			December 31,
			2014			2013
	Buildings		$	13,004		$	11,158
	Office furniture and fixtures			6,706			5,548
	Computer hardware and software			12,949			11,396
	Aircraft			4,668			4,617
				37,327			32,719
	Less accumulated depreciation and amortization			(16,142	)		(13,660	)
				21,185			19,059
	Land			1,490			1,490
			$	22,675		$	20,549

Workers_Compensation_Claims

Workers' Compensation Claims	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Workers' Compensation Claims	6	Workers’ Compensation Claims
	The Company is a self-insured employer with respect to workers’ compensation coverage for all of its employees (including employees co-employed through our client service agreements) working in California, Oregon, Maryland, Delaware and Colorado, except as described below. The Company’s ability to self-insure in California ended on December 31, 2014, as described in more detail below. In the state of Washington, state law allows only the Company’s staffing services and internal management employees to be covered under the Company’s self-insured workers’ compensation program. Additionally, the Company operates a wholly owned fully licensed insurance company, Ecole Insurance Company (“Ecole”), in Arizona to provide workers’ compensation coverage to our employees in Arizona.
	To manage our financial exposure, in the event of catastrophic injuries or fatalities, the Company maintains excess workers’ compensation insurance through our wholly owned captive insurance company, Associated Insurance Company for Excess (“AICE”), with a per occurrence retention of $5.0 million, except in Maryland and Colorado, where our per occurrence retention is $1.0 million and $2.0 million, respectively. AICE maintains excess workers’ compensation insurance coverage with ACE Group (“ACE”), between $5.0 million and $15.0 million per occurrence, except in Maryland, where coverage with ACE is between $1.0 million and $25.0 million per occurrence, and in Colorado, where the coverage with ACE is between $2.0 million and statutory limits per occurrence. Prior to December 1, 2012, similar excess workers’ compensation coverage was through American International Group. The Company continues to evaluate the financial capacity of its insurers to assess the recoverability of the related insurer receivables.
	The Company has provided a total of $216.0 million and $112.4 million at December 31, 2014 and 2013, respectively, as an estimated future liability for unsettled workers’ compensation claims liabilities. The estimated liability for unsettled workers’ compensation claims represents management’s best estimate based upon an actuarial valuation provided by a third party actuary at December 31, 2014 and 2013. Included in the claims liabilities are case reserve estimates for reported losses, plus additional amounts based on projections for incurred but not reported claims and anticipated increases in case reserve estimates. Also included in these estimates are amounts for unallocated loss adjustment expenses, including legal costs. These estimates are continually reviewed and adjustments to liabilities are reflected in current operating results as they become known.
	Our workers’ compensation claims liabilities do not represent an exact calculation of liability, but instead represent management’s best estimate, generally utilizing actuarial expertise and projection techniques, at a given accounting date. The process of estimating unpaid claims and claim adjustment expense involves a high degree of judgment and is subject to a number of variables. These variables can be affected by both internal and external events such as changes in claims handling procedures, changes in individuals involved in the reserve estimation process, legal trends and legislative changes.
	We have undertaken a number of steps during the past two years to improve our workers’ compensation claims administration practices. These steps include hiring additional claim administrators in response to our business growth, and working to close litigated claims more quickly.
	Beginning in late 2013, as part of our efforts to improve our claims handling practices, the Company initiated a specific case reserve study on its open workers’ compensation claims with injury dates in 2012 and earlier. The specific case reserve study resulted in moving dollars from the general reserve of incurred but not reported claims and future loss development into specific case reserves for individual claims. This process was intended to provide management with a more accurate estimate of the ultimate total cost of each claim at a detailed level. Additionally, in mid-2013, the Company initiated a change to its individual claim handling practices by recording specific case reserves on new claims at amounts that include all of the anticipated future costs and working to close claims more quickly with the goal of reducing the ultimate cost of the claims.
	In May 2014, the Company engaged an actuarial consultant to assist management in studying selected historical claims experience and the impact of the change in its claims handling process. During the third quarter of 2014, the Company engaged a new actuary to assist management in determining its best estimate of the Company’s workers’ compensation liability. Based on the work of the new actuary and a thorough review of the Company’s claims handling practices and the results of the work performed by the actuarial consultant engaged during the second quarter of 2014, management reached the conclusion in October 2014 that, based on actuarial methods, the estimate of workers’ compensation liability should reflect a significant increase for the potential development of prior period claims. The Company recorded total workers’ compensation claims expense of $101.2 million during the third quarter of 2014, including a $61.3 million change in estimate relating to prior period claims. Management’s primary considerations in arriving at its estimate of workers’ compensation liability include the significant increase in the Company’s business in recent years, the potential for unexpected future adverse development of open claims, and the increasing complexity and uncertainty surrounding healthcare costs.
	Included in the foregoing liabilities are insured claims that will be paid by the Company’s former excess workers’ compensation insurer and for which the Company has reported a receivable from the insurer for the insured claims liability. Insured claims totaled $781,000 and $768,000 at December 31, 2014 and 2013, respectively.
	Liabilities incurred for work-related employee fatalities and for severely injured workers, as determined by the state in which the accident occurred, are recorded either at an agreed lump-sum settlement amount or the net present value of future fixed and determinable payments over the actuarially determined remaining life expectancy of the beneficiary, discounted at a rate that approximates a long-term, high-quality corporate bond rate. We present our accrued liabilities for workers’ compensation claims on a gross basis along with a corresponding receivable from our insurers, as we are the primary obligor for payment of the related insured claims.
	At December 31, 2014, our long-term workers’ compensation claims liabilities in the accompanying consolidated balance sheet included $271,000 for work-related fatalities. The aggregate undiscounted payout amount related to the catastrophic injuries and fatalities is $360,000. The discount rates applied to the discounted liabilities range from 4.25% to 9.00%. These rates represented the then-current rates for high quality long-term debt securities available at the date of loss with maturities equal to the length of the payout period to the beneficiaries. The actuarially determined payout periods to the beneficiaries range from 7 to 32 years.
	In February 2014, the Company entered into a workers’ compensation insurance arrangement with ACE to provide coverage to BBSI employees in California beginning in the first quarter of 2014. The current agreement is effective through January 2016 with the potential for annual renewals thereafter.
	The arrangement, typically known as a fronted program, provides BBSI a licensed, admitted insurance carrier in California to issue policies on behalf of BBSI without the intention of transferring any of the worker’s compensation risk for the first $5.0 million per claim. The risk of loss up to the first $5.0 million per claim is retained by BBSI through an indemnity agreement.
	During the first quarter of 2014, the Company made an initial deposit of $20.0 million into a trust account established between the Company and ACE related to the new ACE fronted insurance program. The Company began making monthly payments in April 2014 into the trust account to be set aside for the payment of future claims. The balance in the trust account as of December 31, 2014 totaled $50.1 million. The trust account balance is included as a component of the current and long-term restricted marketable securities and workers’ compensation deposits in the accompanying consolidated balance sheet.
	The states of California, Oregon, Maryland, Washington, Delaware and Colorado require us to maintain specified investment balances or other financial instruments, totaling $198.5 million at December 31, 2014 and $72.9 million at December 31, 2013, to cover potential claims losses. In partial satisfaction of these requirements, at December 31, 2014, we have provided surety bonds and standby letters of credit totaling $194.9 million. The investments are included in restricted marketable securities and workers’ compensation deposits in the accompanying consolidated balance sheets. During the fourth quarter of 2014, the state of California increased the Company’s surety deposit requirement to $190.6 million (which is included in the total $194.9 million of surety bonds and standby letters of credit), which the Company satisfied through the posting of third party issued surety bonds which are backed by a $114.3 million letter of credit. In conjunction with this letter of credit, the Company posted $114.3 million of certificates of deposit with Wells Fargo as collateral, this amount is included in long-term assets on the consolidated balance sheet.
	The following table summarizes the aggregate workers’ compensation reserve activity (in thousands):
			Year Ended December 31,
			2014		2013		2012
	Balance at January 1,
	Workers’ compensation claims liabilities		$	112,444	$	70,564	$	51,193
	Claims expense accrual:
	Current year			97,883		63,822		38,386
	Prior years			67,101		23,445		12,344
				164,984		87,267		50,730
	Claims payments related to:
	Current year			13,183		10,586		6,746
	Prior years			48,263		34,801		24,613
				61,446		45,387		31,359
	Balance at December 31,
	Workers’ compensation claims liabilities		$	215,982	$	112,444	$	70,564
	Incurred but not reported (IBNR)		$	113,984	$	69,611	$	47,992

Revolving_Credit_Facility_and_

Revolving Credit Facility and Long-Term Debt	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Revolving Credit Facility and Long-Term Debt	7	Revolving Credit Facility and Long-Term Debt
	Effective December 29, 2014, the Company entered into a new credit agreement (the “Agreement”) with its principal bank, Wells Fargo Bank, National Association (the “Bank”). The Agreement provides for a $40.0 million term loan maturing December 31, 2016, as well as a $14.0 million revolving credit line, with a $5.0 million sublimit for unsecured standby letters of credit. The Company had no outstanding borrowings on its revolving credit line at December 31, 2014. The Agreement also provides for an increase to a total of $114.3 million in cash-secured letters of credit to satisfy collateral requirements associated with various surety deposit requirements for workers’ compensation purposes in the state of California. In conjunction with this letter of credit, the Company posted $114.3 million of certificates of deposit with Wells Fargo as collateral, which is included in long-term assets on the consolidated balance sheet. The Agreement includes a non-refundable commitment fee of $400,000, which is reported within prepaid expenses and other on the Company’s consolidated balance sheet. The fee will be amortized to interest expense ratably over the term of the loan.
	The $40.0 million term loan with the Bank requires payments of $3.0 million on June 30, 2015, $7.0 million on September 30, 2015, $15.0 million on December 31, 2015, $5.0 million on June 30, 2016 and $5.0 million on September 30, 2016. The term loan bears interest at the one month LIBOR plus 4.0%.
	Advances under the revolving credit facility bear interest as selected by the Company of either (a) a daily floating rate of one month LIBOR plus 2% or (b) a fixed rate of LIBOR plus 2.0% The Agreement also provides for an unused commitment fee of 0.35% per year on the average dailyunused amount of the revolving credit facility, and a fee of 1.75% of the face amount of each letter of credit
	The credit facility is collateralized by the Company’s accounts receivable and other rights to receive payment, general intangibles, inventory and equipment.
	The Agreement requires the satisfaction of certain financial covenants as follows:
		•	minimum Fixed Charge Coverage ratio of no less than 1.5:1.0, measured quarterly on a rolling four-quarter basis; and
		•	ratio of restricted and unrestricted cash and marketable securities to workers’ compensation and safety incentive liabilities of at least 1.0:1.0, measured quarterly;
	The Agreement includes certain additional covenants as follows:
		•	capital expenditures may not exceed a total of $5.0 million in 2015 and a total of $4.0 million in 2016 without the Bank’s prior approval;
		•	prohibition on incurring additional indebtedness without the prior approval of the Bank, other than up to $200,000 per year in purchase money financing and the aggregate of all purchase money indebtedness does not exceed $400,000 at any time;
		•	prohibition on repurchases of the Company’s common stock; and
		•	continuation of quarterly cash dividends up to $0.22 per share so long as there is no default by the Company and payment would not cause a default.
	The Agreement also contains customary events of default. If an event of default under the Agreement occurs and is continuing, the Bank may declare any outstanding obligations under the Agreement to be immediately due and payable. The Company was in compliance with all applicable financial covenants at December 31, 2014.
	Additionally, the Company maintains a term loan with the Bank with a current balance of approximately $5.1 million secured by the Company’s corporate office building in Vancouver, Washington. The term loan requires payment of monthly installments of $18,375, bearing interest at the one month LIBOR plus 2.25%, with the unpaid principal balance due November 1, 2017.

401k_Savings_Plan

401(k) Savings Plan	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
401(k) Savings Plan	8	401(k) Savings Plan
	We have a Section 401(k) Retirement Savings Plan for the benefit of our eligible employees. All staffing and management employees 21 years of age or older become eligible to participate in the savings plan upon completion of 1,000 hours of service in any consecutive 12-month period following the initial date of employment. Employees covered under a PEO arrangement may participate in the plan at the sole discretion of the PEO client. The determination of discretionary Company contributions to the plan, if any, is at the sole discretion of our Board of Directors. No discretionary Company contributions were made to the plan for the years ended December 31, 2014, 2013 and 2012.
	We make matching contributions to the 401(k) plan under a safe harbor provision, whereby the Company matches 100% of contributions by management and staffing employees up to 3% of each participating employee’s annual compensation; and 50% of the employee’s contributions up to an additional 2% of annual compensation. We made $885,000, $734,000 and $610,000 in matching contributions during 2014, 2013 and 2012, respectively. Participants’ interests in Company safe harbor contributions to the plan are fully vested when made.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	9	Commitments and Contingencies
	Lease commitments
	We lease office space for our branch offices under operating lease agreements that require minimum annual payments as follows (in thousands):
	Year ending
	December 31,
	2015		$	3,502
	2016			2,874
	2017			2,233
	2018			1,349
	2019			666
	2020			60
	Thereafter			0
			$	10,684
	Rent expense was approximately $3.7 million, $3.2 million, and $2.8 million for the years ended December 31, 2014, 2013 and 2012, respectively.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	10	Income Taxes
	The provision for income taxes from continuing operations is as follows (in thousands):
			Year ended December 31,
			2014			2013			2012
	Current:
	Federal		$	(8,022	)	$	6,386		$	5,378
	State			(741	)		1,225			685
				(8,763	)		7,611			6,063
	Deferred:
	Federal			(10,237	)		(519	)		341
	State			747			(82	)		(76	)
				(9,490	)		(601	)		265
	Total (benefit) provision		$	(18,253	)	$	7,010		$	6,328
	Deferred income tax assets and liabilities are comprised of the following components (in thousands):
			December 31,
			2014			2013
	Gross deferred income tax assets:
	Workers’ compensation claims liabilities		$	12,168		$	6,985
	Safety incentives payable			3,782			3,529
	Allowance for doubtful accounts			118			94
	Tax effect of unrealized losses, net			856			959
	Alternative minimum tax credit carryforward			1,840			0
	State credit carryforward			969			805
	State loss carryforward			568			0
	Workers’ opportunity tax credit and EZ credit carryforward			3,162			0
	Other			605			504
				24,068			12,876
	Less valuation allowance			1,078			1,763
				22,990			11,113
	Gross deferred income tax liabilities:
	Tax depreciation in excess of book depreciation			(3,770	)		(2,793	)
	Tax amortization of goodwill			(11,588	)		(10,178	)
				(15,358	)		(12,971	)
	Net deferred income tax assets (liabilities)		$	7,632		$	(1,858	)
	The effective tax rate for continuing operations differed from the U.S. statutory federal tax rate due to the following:
			Year ended December 31,
			2014			2013			2012
	Statutory federal tax rate			(35.0	)%		35	%		35	%
	State taxes, net of federal benefit			0.2			3.4			0.4
	Valuation allowance on capital loss carryforward and state tax credit carryforward			(.2	)		(.4	)		2.3
	Adjustment for final positions on filed returns			(.7	)		(1.5	)		(.3	)
	Nondeductible expenses and other, net			2.2			0.8			4.4
	Federal tax-exempt interest income			(.2	)		(.2	)		(.4	)
	Federal and state tax credits			(6.6	)		(8.9	)		(8.9	)
				(40.3	)%		28.2	%		32.5	%
	The Company has established a valuation allowance for certain deferred tax assets due to uncertainties regarding the Company’s ability to generate future taxable investment gains in order to utilize certain investment impairment losses and investment loss carry forwards for tax purposes. The realization of a significant portion of net deferred tax assets is based in part on our estimates of the timing of reversals of certain temporary differences and on the generation of taxable income before such reversals. At December 31 2014, we maintained a valuation allowance for approximately $1.1 million of federal and state tax benefits that are not expected to be utilized.
	Under ASC 740, “Income Taxes,” management evaluates the realizability of the deferred tax assets on a quarterly basis under a “more-likely than not” standard. As part of this evaluation, management reviews all evidence both positive and negative to determine if a valuation allowance is needed. One component of this analysis is to determine whether the Company was in a cumulative loss position for the most recent 12 quarters. Despite the increase to the workers’ compensation reserve in the third quarter of 2014, the Company was in a cumulative income position for the 12 quarters ended December 31, 2014.
	Management’s review of positive evidence included the existence of federal and California taxable income in eligible carryback years, reversal of temporary items, and projection of future taxable income. The projection of future taxable income was a significant factor in management’s determination that no additional valuation allowance was required at December 31, 2014. Management’s projections of taxable income are based on the existence of signed annual contracts with the Company’s PEO customer base, objective evidence that the Company’s customers are retained at a high rate over long periods, and objective evidence that recent price increase initiatives are being accepted by the Company’s customer base.
	Management has continued to improve the Company’s procedures in many areas of its self-insured workers’ compensation program over the past two years as described in Note 6. The results of these efforts have improved management’s ability to project workers’ compensation expense. Management will monitor the need for an additional valuation allowance at each quarter in the future and, if the negative evidence outweighs the positive evidence, an allowance will be recorded.
	The Company is subject to Income taxes in U.S. federal and multiple state and local tax jurisdictions. In the major jurisdictions where the Company operates, it is generally no longer subject to income tax examinations by tax authorities for years before 2010. As of December 31, 2014 and 2013, the Company had no unrecognized tax benefits.
	A portion of the consolidated income the Company generates is not subject to state income tax. Depending on the percentage of this income to total consolidated income, the Company’s state effective rate can fluctuate from expectations. As a result of the mix of income subject to state income tax, total state tax expense decreased by approximately $4,000, $284,000 and $498,000 in 2014, 2013 and 2012, respectively.
	At December 31, 2014, the Company had capital loss carry forward of approximately $2.1 million. The carry forward will expire unless utilized in tax years on or before December 31, 2015. At December 31, 2014, the Company had federal general business tax credit carry forwards of approximately $3.2 million. The carry forwards will expire unless utilized in tax years on or before December 31, 2024. The Company also had an alternative minimum tax credit carry forward of approximately $1.8 million. The credit carry forward has an indefinite life and will not expire until utilized.
	At December 31, 2014, the Company had state tax credit carry forwards of approximately $1.5 million. The carryforwards expire unless utilized in tax years on or before December 31, 2024. At December 31, 2014, the Company had a California net operating loss carry forward of approximately $6.7 million. The carry forward will expire unless utilized in tax years on or before December 31, 2034. In addition, the Company had a total of approximately $3.9 million in net operating loss carry forwards from other states that will expire unless utilized in tax years between December 31, 2021 and December 31, 2034.

Stock_Incentive_Plans

Stock Incentive Plans	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Incentive Plans	11	Stock Incentive Plans
	The Company’s 2009 Stock Incentive Plan (the “2009 Plan”), which provides for stock-based awards to Company employees, non-employee directors and outside consultants or advisors, was approved by shareholders on May 13, 2009. No stock-based awards have been issued to outside consultants or advisors. The number of shares of common stock reserved for issuance under the 2009 Plan is 1,000,000, of which the aggregate number of shares for which incentive stock options may be granted under the Plan is 900,000. No new grants of stock options may be made under the Company’s 2003 Stock Incentive Plan (the “2003 Plan”). At December 31, 2014, there were option awards covering 367,533 shares outstanding under the 2009 Plan, together with the 2003 Plan and its predecessor, the 1993 Stock Incentive Plan. Outstanding options under all the plans generally expire ten years after the date of grant. Options are generally exercisable in four equal annual installments beginning one year after the date of grant. At December 31, 2014, there are 126,846 restricted stock units outstanding.
	The Company recognizes compensation expense for options awarded under its stock incentive plans based on the grant-date fair value. Compensation expense is attributed to earnings using the straight-line method over the requisite service period.
	A summary of the status of the Company’s stock options at December 31, 2014, 2013 and 2012, together with changes during the periods then ended, is presented below:
			Number			Weighted
			of			average
			options			exercise
						price
	Outstanding at December 31, 2011			671,294
	Options granted at market price			7,500			17.55
	Options exercised			(131,997	)		13.98
	Options cancelled			(8,100	)		13.85
	Outstanding at December 31, 2012			538,697
	Options exercised			(138,298	)		13.53
	Outstanding at December 31, 2013			400,399
	Options exercised			(32,866	)		13.24
	Outstanding at December 31, 2014			367,533
	Available for grant at December 31, 2014			481,999
	The following tables presents information on stock options exercised and outstanding:
			Year Ended
			December 31,
	(in thousands, except share data)		2014			2013
	Intrinsic value of options exercised in the period		$	1,025		$	6,089
	($ in thousands, except share data)		Number			Weighted		Weighted				Aggregate
			of			Average		Average				Intrinsic
			Shares			Exercise		Remaining				Value
						Price		Contractual
								Term (Years)
	Stock options:
	Outstanding December 31, 2014			367,533		$	15.22		5.25			$	4,478
	Exercisable at December 31, 2014			221,059			14.45		4.55				2,847
	The aggregate intrinsic value of stock options represents the difference between the Company’s closing stock price at the end of the period and the relevant exercise price multiplied by the number of options outstanding at the end of the period at each such price.
	The fair value of stock option awards as determined under the Black-Scholes option-pricing model was estimated with the following weighted-average assumptions:
			2012
	Expected volatility			65.9	%
	Risk free interest rate			2.9	%
	Expected dividend yield			2.5	%
	Expected term			7.3 years
	Weighted average fair value per share		$	9.08
	There were no options granted during 2014 or 2013. There were no options granted during 2012 below market price.
	During 2014, 2013 and 2012, the Company granted 69,371, 44,970 and 47,500 restricted stock units at a weighted average grant date fair value of $50.47, $50.28 and $21.44 per share, respectively, which represented the closing price of the Company’s stock on the date of grant. The restricted stock units vest in four equal annual installments beginning one year following the date of grant.
	The following table presents restricted stock unit activity:
			Units			Weighted Average
						Grant Date
						Fair Value
	Non-vested at December 31, 2011			0		$	0
	Granted			47,500			21.44
	Non-vested at December 31, 2012			47,500			21.44
	Granted			44,970			50.28
	Vested			(10,302	)		21.44
	Cancelled/Forfeited			(1,573	)		21.44
	Non-vested at December 31, 2013			80,595			37.53
	Granted			69,371			50.47
	Vested			(15,253	)		33.4
	Cancelled/Forfeited			(7,867	)		34.9
	Non-vested at December 31, 2014			126,846			44.99
	The following table summarizes stock-based compensation expense related to stock option and restricted stock unit awards (in thousands):
			Year Ended
			December 31,
			2014			2013		2012
	Stock-based compensation expense included in selling, general and administrative expenses		$	1,699		$	1,016	$	695
	Deferred income taxes			675			404		272
	Stock-based compensation expense related to stock options and restricted stock units, net of tax		$	1,024		$	612	$	423
	As of December 31, 2014, unrecognized compensation expense related to stock options and restricted stock units was $5.6 million with a weighted average remaining contractual period of 3.15 years.
The following table summarizes information about stock options outstanding at December 31, 2014:
Options outstanding									Options exercisable
Exercise price range		Number			Weighted-		Weighted-		Exercisable				Weighted-
		of			average		average		at				average
		shares			exercise		remaining		December 31,				exercise
					price		contractual		2014				price
							life (years)
$2.01 - $  2.58			2,250		$	2.29	Indefinite			2,250			$	2.29
8.82 -  17.55			365,283			15.29	5.3			218,809				14.57
			367,533			15.22				221,059				14.45

Stock_Repurchase_Program

Stock Repurchase Program	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Stock Repurchase Program	12	Stock Repurchase Program
	The Company maintains a stock repurchase program approved by the Board of Directors, which authorizes the repurchase of shares from time to time in open market purchases. The repurchase program currently allows for the repurchase of approximately 1.1 million additional shares as of December 31, 2014.
	During 2014, we repurchased 87,200 shares at a weighted average price of $42.16. No share repurchases were made under the repurchase program during 2013 and 2012.

Litigation

Litigation	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Litigation	13	Litigation
	On November 6, 2014, plaintiffs in Michael Arciaga, et al. v. Barrett Business Services, Inc., et al., filed an action in the United States District Court for the Western District of Washington against the Company and Michael L. Elich and James D. Miller, the Company’s Chief Executive Officer and Chief Financial Officer, respectively. The action purports to be a class action brought on behalf of all Company stockholders alleging violations of the federal securities laws. The claims arise from the decline in the market price for the Company’s common stock following announcement of a charge for increased workers compensation reserves expense. The lawsuit seeks compensatory damages (in an amount to be determined at trial), plus interest, and costs and expenses (including attorney fees and expert fees).
	On November 13, 2014, a second purported shareholder class action was filed in the United States District Court for the Western District of Washington, entitled Christopher P. Carnes, et al. v. Barrett Business Services, Inc., et al. The Carnes complaint names the same defendants as the Arciaga case and asserts similar claims for relief.
	Similarly, on November 17, 2014, a third purported shareholder class action was filed in the United States District Court for the Western District of Washington, entitled Shiva Stein, et al. v. Barrett Business Services, Inc., et al. The Stein complaint names the same defendants as the Arciaga and Carnes cases and asserts similar claims for relief.
	On February 25, 2015, the court ordered consolidation of the three cases, and any new or other cases involving the same subject matter, into a single action for pretrial purposes. The court also appointed the Painters & Allied Trades District Council No. 35 Pension and Annuity Funds as the lead plaintiff. Discovery has not been undertaken as it is automatically stayed under the federal Private Securities Litigation Reform Act.
	On February 27, 2015, the Company received a letter from counsel for an alleged stockholder accusing each of the Company’s directors and officers with having breached his fiduciary duties of loyalty and good faith based on the same facts as those alleged in the three lawsuits described above, as well as that certain officers and directors sold shares of the Company’s stock while in possession of material non-public information. The letter asserts that the Company has sustained and continues to sustain damages, including the costs and expenses incurred in connection with the Company’s reserve strengthening process, reserve study and consultants, the cost of stock repurchases in October 2014, compensation paid to the Company’s officers, and costs of negotiating the Company’s credit facility with its principal lender The letter demands that the Company’s Board of Directors take action against each of the Company’s officers and directors to recover these damages and the proceeds of sales of stock by the officers and directors during 2013 and 2014. The letter states that if the Board does not take these actions within a reasonable period, the stockholder will commence a shareholder derivative action on behalf of the Company.
	Management is unable to estimate the probability, or the potential range, of loss arising from these legal actions.
	The Company is subject to other legal proceedings and claims, which arise in the ordinary course of our business. In the opinion of management, the amount of ultimate liability with respect to currently pending or threatened actions is not expected to materially affect the consolidated financial position or results of operations of the Company.

Quarterly_Financial_Informatio

Quarterly Financial Information	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information	14	Quarterly Financial Information (Unaudited)
	(in thousands, except per share amounts and market price per share)
			First			Second		Third			Fourth
			Quarter			Quarter		Quarter			Quarter
	Year ended December 31, 2014
	Revenues		$	135,140		$	151,069	$	174,959		$	175,016
	Cost of revenues			125,834			121,217		217,741			140,975
	Net (loss) income			(3,583	)		7,283		(37,818	)		7,034
	Basic (loss) earnings per share			(0.50	)		1.02		(5.27	)		0.99
	Diluted (loss) earnings per share			(0.50	)		0.98		(5.27	)		0.97
	Common stock market prices:
	High			102.2			63.19		63.45			45.38
	Low			57.82			41.96		39.47			18.25
	Year ended December 31, 2013
	Revenues		$	111,551		$	128,798	$	147,971		$	144,524
	Cost of revenues			103,240			105,072		117,785			120,223
	Net (loss) income			(2,549	)		5,886		8,994			5,561
	Basic (loss) earnings per share			(0.36	)		0.83		1.26			0.78
	Diluted (loss) earnings per share			(0.36	)		0.8		1.21			0.74
	Common stock market prices:
	High			53.27			62.82		73.49			98
	Low			38.15			48.5		48.08			66.33

Summary_of_Operations_and_Sign1

Summary of Operations and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Nature of operations	Nature of operations
	Barrett Business Services, Inc. (“BBSI”, the “Company”), is a leading provider of business management solutions for small-and mid-sized companies. The Company has developed a management platform that integrates a knowledge-based approach from the management consulting industry with tools from the human resource outsourcing industry. This platform, through the effective leveraging of human capital, assists our business owner clients in more effectively running their business. We believe this platform, delivered through a decentralized organizational structure, differentiates BBSI from our competitors. The Company operates through a network of branch offices throughout California, Oregon, Washington, Idaho, Arizona, Nevada, Utah, Colorado, Maryland, Delaware and North Carolina. Approximately 77%, 74% and 69%, respectively, of our revenue during 2014, 2013 and 2012 was attributable to our California operations. BBSI was incorporated in Maryland in 1965.
	The Company operates a wholly owned captive insurance company, Associated Insurance Company for Excess (“AICE”). AICE is a fully licensed captive insurance company holding a certificate of authority from the Arizona Department of Insurance. The purpose of AICE is twofold: (1) to provide access to more competitive and cost effective insurance markets and (2) to provide additional flexibility in cost effective risk management. The captive handles the Company’s workers’ compensation claims occurring on or after January 1, 2007. AICE provides excess workers’ compensation coverage from $1.0 million up to $5.0 million per occurrence in the states of California, Oregon, Delaware and Washington. AICE also provides general liability insurance coverage for BBSI.
	The Company also operates a wholly owned insurance company, Ecole Insurance Company (“Ecole”). Ecole is a fully licensed insurance company holding a certificate of authority from the Arizona Department of Insurance. Ecole provides workers’ compensation coverage to the Company’s employees working in Arizona beginning with claims occurring on or after March 1, 2010. The restricted capital used to capitalize the insurance company was approximately $6.1 million and is included in restricted marketable securities and workers’ compensation deposits in our consolidated balance sheets.
Principles of consolidation	Principles of consolidation
	The accompanying financial statements are prepared on a consolidated basis. All significant intercompany account balances and transactions between BBSI, AICE, Ecole and BBS I, LLC, the aircraft subsidiary which owns an aircraft for management’s operational travel needs, have been eliminated in consolidation.
Reportable Segment	Reportable Segment
	The Company has one principal operating and reporting segment. The chief operating decision maker (currently our Chief Executive Officer) regularly reviews the financial information of our business at a consolidated level in deciding how to allocate resources and assessing performance.
Revenue recognition	Revenue recognition
	We recognize revenue as services are rendered by our workforce. Professional employer (PEO) services are normally used by organizations to satisfy ongoing needs related to the management of human capital and are governed by the terms of a client services agreement with a minimum term of one year, which cover all employees at a particular work site. Our client services agreements are renewable on an annual basis and typically require 30 days’ written notice to cancel or terminate the contract by either party. Our client services agreements provide for immediate termination upon any default of the client regardless of when notice is given. We report PEO revenues on a net basis because we are not the primary obligor for the services provided by our clients to their customers pursuant to our client services agreements. Consequently, these service fee revenues represent the gross margin generated from our professional employer services after deducting the amounts invoiced to our clients for direct payroll expenses such as salaries, wages, health insurance, employee out-of-pocket expenses incurred incidental to employment, and safety incentives. These amounts are also excluded from cost of revenues. Professional Employer service fees also include amounts invoiced to our clients for employer payroll-related taxes and workers’ compensation coverage. Staffing services are engaged by customers to meet short-term and long-term personnel needs.
Cost of revenues	Cost of revenues
	Our cost of revenues for PEO services includes employer payroll related taxes and workers’ compensation. Our cost of revenues for staffing services is comprised of direct payroll costs, employer payroll related taxes, employee benefits, and workers’ compensation. Direct payroll costs represent the gross payroll earned by staffing services employees based on salary or hourly wages. Payroll taxes and employee benefits consist of the employer’s portion of Social Security and Medicare taxes, federal and state unemployment taxes, and staffing services employee reimbursements for materials, supplies and other expenses, which are paid by our customer. Workers’ compensation costs consist primarily of the costs associated with our self-insured workers’ compensation program, such as claims reserves, claims administration fees, legal fees, state administrative agency fees and excess insurance premiums for catastrophic injuries.
	We maintain separate workers’ compensation insurance policies for employees working in states where the Company is not self-insured. Safety incentives represent cash incentives paid to certain client companies engaged in a client services agreement, for maintaining safe-work practices in order to minimize workplace injuries. The incentive is based on a percentage of annual payroll and is paid annually to clients who meet predetermined workers’ compensation claims cost objectives.
Cash and cash equivalents	Cash and cash equivalents
	We consider non-restricted short-term investments, which are highly liquid, readily convertible into cash, and have original maturities of less than three months, to be cash equivalents for purposes of the consolidated statements of cash flows. A substantial portion of the Company’s cash and cash equivalents is invested in tax-exempt money market funds managed by the Company’s principal bank. The Company maintains cash balances in bank accounts that normally exceed FDIC insured limits. The Company has not experienced any losses related to its cash concentration.
Marketable securities	Marketable securities
	As of December 31, 2014, the Company’s marketable securities consisted of tax-exempt municipal securities, U.S. Treasuries, variable rate demand notes (VRDN) and corporate bonds. We determine the appropriate classification for certain investments in debt securities, and classify our marketable securities as trading or available-for-sale. The Company classifies municipal securities, U.S. Treasuries, VRDN, and corporate bonds as available for sale; they are reported at fair value with unrealized gains and losses, net of taxes, shown as a component of accumulated other comprehensive (loss) income in stockholders’ equity. Management considers available evidence in evaluating potential impairment of investments, including the duration and extent to which fair value is less than cost and the Company’s ability and intent to hold the investments. In the event a loss is determined to be other-than-temporary, the loss will be recognized in the consolidated statements of operations.
Restricted marketable securities	Restricted marketable securities
	At December 31, 2014 and 2013, restricted marketable securities consisted of money market funds held in trust, U.S. Treasures, municipal debt instruments, and corporate debt instruments with maturities generally from 180 days to two years (see Note 3, Note 4 and Note 6). At December 31, 2014 and 2013, the approximate fair value of restricted marketable securities equaled their approximate amortized cost. Restricted marketable securities have been categorized as available-for-sale; they are reported at fair value with unrealized gains and losses, net of taxes, shown as a component of accumulated other comprehensive (loss) income in stockholders’ equity. Realized gains and losses on sales of restricted marketable securities are included in other income (expense) on our consolidated statements of operations.
Allowance for doubtful accounts	Allowance for doubtful accounts
	We must make estimates of the collectability of our accounts receivable for services provided to our customers. Our management analyzes historical bad debts, customer concentrations, customer credit-worthiness, current economic conditions, and changes in customers’ payment trends when evaluating the adequacy of the allowance for doubtful accounts. If the financial condition of our customers deteriorates, resulting in an impairment of their ability to make payments, additional allowances may be required.
	Our allowance for doubtful accounts activity is summarized as follows (in thousands):
		2014			2013			2012
	Balance at January 1,
	Allowance for doubtful accounts	$	242		$	381		$	452
	Charges to expense		103			300			195
	Write-offs of uncollectible accounts, net of recoveries		(54	)		(439	)		(266	)
	Balance at December 31,
	Allowance for doubtful accounts	$	291		$	242		$	381
Income taxes	Income taxes
	Our income taxes are accounted for using an asset and liability approach. This requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statement and tax basis of assets and liabilities at the applicable tax rates. A valuation allowance is recorded against deferred tax assets if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The factors used to assess the likelihood of realization include the Company’s forecast of the reversal of temporary differences, future taxable income and available tax planning strategies that could be implemented to realize the net deferred tax assets. Failure to achieve forecasted taxable income in applicable tax jurisdictions could affect the ultimate realization of deferred tax assets and could result in an increase in the Company’s effective tax rate on future earnings.
	The determination of our provision for income taxes requires significant judgment, the use of estimates, and the interpretation and application of complex tax laws. Significant judgment is required in assessing the timing and amounts of deductible and taxable items and the probability of sustaining uncertain tax positions. The Company recognizes the tax benefit from uncertain tax positions if it is more likely than not that the tax positions will be sustained on examination by the tax authorities, based on the technical merits of the position. The tax benefit is measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. As facts and circumstances change, we reassess these probabilities and would record any changes in the consolidated financial statements as appropriate. The Company recognizes interest and penalties related to unrecognized tax benefits in income tax expense.
Business combinations	Business combinations
	We account for business combinations using the acquisition method of accounting. Transaction costs incurred in connection with a business combination are expensed as incurred. Changes in deferred tax asset valuation allowances and acquired income tax uncertainties after the measurement period are recognized in earnings.
Goodwill and intangible assets	Goodwill and intangible assets
	Goodwill is recorded as the difference, if any, between the aggregate consideration paid for a business combination and the fair value of the net assets acquired. Goodwill is not amortized, but is evaluated for impairment annually, or more frequently if indicators of impairment are present or changes in circumstances suggest that impairment may exist. The Company has one reporting unit and evaluates the carrying value of goodwill annually at December 31. No impairment has been recognized in the periods presented.
	Our intangible assets with definite lives are amortized on a straight-line basis over their estimated economic useful lives.
Property, equipment and software	Property, equipment and software
	Property, equipment and software are stated at cost. Expenditures for maintenance and repairs are charged to operating expense as incurred and expenditures for additions and improvements are capitalized. The cost of assets sold or otherwise disposed of and the related accumulated depreciation are eliminated from the accounts, and any resulting gain or loss is reflected in the consolidated statements of operations.
	Depreciation of property, equipment and software is calculated using either straight-line or accelerated methods over estimated useful lives of the related assets or lease terms, as follows:
		Years
	Buildings	39
	Office furniture and fixtures	7
	Computer hardware and software	10-Mar
	Aircraft	20
	Leasehold improvements	Shorter of lease term or estimated useful life
Impairment of long-lived assets	Impairment of long-lived assets
	Long-lived assets, such as property, equipment and software and acquired intangibles, subject to amortization, are reviewed for impairment annually, or whenever events or changes in circumstances indicate that the remaining estimated useful life may warrant revision or that the carrying amount of an asset may not be recoverable. Some of the events or changes in circumstances that would trigger an impairment review include, but are not limited to, significant under-performance relative to expected and/or historical results (such as two years of significant sales declines or two years of significant negative operating cash flows), significant negative industry or economic trends, or knowledge of transactions involving the sale of similar property at amounts below the carrying value.
	Assets are grouped for recognition and measurement of impairment at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets. If the carrying amount of an asset group exceeds the estimated, undiscounted future cash flows expected to be generated by the asset, then an impairment charge is recognized to the extent the carrying amount exceeds the asset’s fair value. In determining fair value, management considers current results, trends, future prospects, and other economic factors.
Workers' compensation claims liabilities	Workers’ compensation claims liabilities
	The estimated liability for unsettled workers’ compensation claims represents an evaluation of information provided by our internal claims adjusters and our third-party administrators for workers’ compensation claims, coupled with an actuarial estimate of future cost development of reported claims and incurred but not reported claims (together, IBNR) provided by the Company’s independent actuary. Included in the claims liabilities are case reserve estimates for reported losses, plus additional amounts for estimated future development of reported claims and incurred but not reported claims as well as estimates for unallocated loss adjustment expenses, including legal costs. These estimates are continually reviewed and adjustments to liabilities are reflected in current operating results as they become known.
	The Company’s independent actuary provides management with an estimate of the current portion and long-term portion of our total workers’ compensation claims. The current portion represents the best estimate of 2014 and prior year claims expected to be paid out in 2015. The Company will also pay out a portion of the 2015 claims during 2015.
	Our workers’ compensation claims liabilities do not represent an exact calculation of liability, but instead represent management’s best estimate, generally utilizing actuarial expertise and projection techniques, at a given accounting date. The process of estimating unpaid claims and claim adjustment expense involves a high degree of judgment and is subject to a number of variables. These variables can be affected by both internal and external events such as changes in claims handling and reserve estimation procedures, changes in individuals involved in the reserve estimation process, inflation, legal trends and legislative changes.
	We use informed judgment throughout the process, derived from individual experiences and expertise applied to multiple sets of data and analysis. We consider all significant facts and circumstances known at the time loss reserves are established and as new facts and circumstances become known. Due to the inherent uncertainty underlying loss reserve estimates including, but not limited to, the future settlement environment, final resolution of our estimated liability for our workers’ compensation claims will likely be higher or lower than the related loss reserves at the reporting date. Therefore, actual paid losses, as specific claims are settled in the future, may be materially different in amount from our current loss reserves.
	A basic premise in most actuarial analyses is that historical data and past patterns demonstrated in the incurred and paid historical data form a reasonable basis upon which to project future outcomes, absent a material change. To the extent a material change affecting the ultimate claim liability is known, such change is quantified to the extent possible through an analysis of internal Company data and, if available and when appropriate, external data. Significant structural changes to the available data can materially impact the reserve estimation process. Actuaries exercise a considerable degree of judgment in the evaluation of these factors in their analysis of reserves. The application of actuarial judgment is unavoidable when faced with material uncertainty. Different actuaries may choose different assumptions when faced with such uncertainty, based on their individual backgrounds, professional experiences and the context in which they are reviewing the reserves. Hence, the estimates selected by different actuaries may differ materially from each other.
Safety incentives liability	Safety incentives liability
	Safety incentives represent cash incentives paid to certain PEO client companies for maintaining safe-work practices in order to minimize workplace injuries. The incentive is based on a percentage of annual payroll and is paid annually to customers who meet predetermined workers’ compensation claims cost objectives. Safety incentive payments are made only after closure of all workers’ compensation claims incurred during the customer’s contract period. The liability is estimated and accrued each month based upon contract year-to-date payroll and the then-current amount of the customer’s estimated workers’ compensation claims reserves as established by us and our third party administrator and the expected payout as determined by historical incentive payment trends. Safety incentive expense is netted against PEO services revenue in our consolidated statements of operations.
Customer deposits	Customer deposits
	We require deposits from certain PEO customers to cover a portion of our accounts receivable due from such customers in the event of default of payment.
Comprehensive (loss) income	Comprehensive (loss) income
	Comprehensive (loss) income includes all changes in equity during a period except those that resulted from investments by or distributions to the Company’s stockholders.
	Other comprehensive (loss) income refers to revenues, expenses, gains and losses that under generally accepted accounting principles are included in comprehensive (loss) income, but excluded from net (loss) income as these amounts are recorded directly as an adjustment to stockholders’ equity. Our other comprehensive (loss) income is comprised of unrealized holding gains and losses on our available for sale marketable securities.
Statements of cash flows	Statements of cash flows
	Interest paid during 2014, 2013 and 2012 did not materially differ from interest expense.
	Income taxes paid by the Company in 2014, 2013 and 2012 totaled $3.3 million, $9.0 million and $3.3 million, respectively.
Basic and diluted earnings per share	Basic and diluted earnings per share
	Basic earnings per share are computed based on the weighted average number of common shares outstanding for each year using the treasury method. Diluted earnings per share reflect the potential effects of the exercise of outstanding stock options. Basic and diluted shares outstanding are summarized as follows (in thousands):
		Year Ended
		December 31,
		2014			2013			2012
	Weighted average number of basic shares outstanding		7,160			7,105			7,723
	Effect of dilutive securities		0			292			140
	Weighted average number of diluted shares outstanding		7,160			7,397			7,863
	As a result of the net loss for the year ended December 31, 2014, 227,000 potential common shares have been excluded from the calculation of diluted loss per share because their effect would be anti-dilutive.
Reclassifications	Reclassifications
	Certain prior year amounts have been reclassified to conform to the 2014 presentation. Such reclassifications had no impact on the Company’s financial condition, operating results, cash flows, working capital or stockholder’s equity.
Accounting estimates	Accounting estimates
	The preparation of our consolidated financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Estimates are used for carrying values of marketable securities, allowance for doubtful accounts, deferred income taxes, carrying values for goodwill and property and equipment, accrued workers’ compensation liabilities and safety incentive liabilities. Actual results may or may not differ from such estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09 Revenue from Contracts with Customers, which will supersede nearly all existing revenue recognition guidance under U.S. GAAP. The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The new standard is effective for the Company on January 1, 2017. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method or determined the effect of the standard on its ongoing financial reporting.
	In September 2014, the FASB issued new accounting guidance on disclosure of uncertainties about an entity’s ability to continue as a going concern. The new guidance requires an entity’s management to evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued, and if so, disclose that fact. Management is also required to evaluate and disclose whether its plans alleviate that doubt. The guidance is effective for us in 2017 and will be applicable to both annual and interim reporting periods. We do not expect the adoption of this guidance to have an impact on our consolidated financial statements.

Summary_of_Operations_and_Sign2

Summary of Operations and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Allowance for Doubtful Accounts	Our allowance for doubtful accounts activity is summarized as follows (in thousands):
		2014			2013			2012
	Balance at January 1,
	Allowance for doubtful accounts	$	242		$	381		$	452
	Charges to expense		103			300			195
	Write-offs of uncollectible accounts, net of recoveries		(54	)		(439	)		(266	)
	Balance at December 31,
	Allowance for doubtful accounts	$	291		$	242		$	381
Summary of Property, Equipment and Software Over Estimated Useful Life	Depreciation of property, equipment and software is calculated using either straight-line or accelerated methods over estimated useful lives of the related assets or lease terms, as follows:
		Years
	Buildings	39
	Office furniture and fixtures	7
	Computer hardware and software	10-Mar
	Aircraft	20
	Leasehold improvements	Shorter of lease term or estimated useful life
Summary of Basic and Diluted Common Shares Outstanding	Basic and diluted shares outstanding are summarized as follows (in thousands):
		Year Ended
		December 31,
		2014			2013			2012
	Weighted average number of basic shares outstanding		7,160			7,105			7,723
	Effect of dilutive securities		0			292			140
	Weighted average number of diluted shares outstanding		7,160			7,397			7,863

Fair_Value_Measurement_Tables

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Summary of Marketable Securities Consist of Investments	Marketable securities consist of the following (in thousands):
		December 31, 2014							December 31, 2013							Fair
																Value
		Cost		Gross			Recorded		Cost		Gross			Recorded		Category
				Unrealized			Basis				Unrealized			Basis
				Gains							(Losses)
				(Losses)
	Current:
	Available-for-sale:
	VRDN	$	21,670	$	0		$	21,670	$	10,000	$	0		$	10,000		2
	Certificates of deposit		8,330		(43	)		8,287		0		0			0		2
	Corporate bonds		0		0			0		9,800		(13	)		9,787		2
		$	30,000	$	(43	)	$	29,957	$	19,800	$	(13	)	$	19,787
	Long term:
	Available-for-sale:
	Municipal bonds	$	3,843	$	7		$	3,850	$	4,074	$	(17	)	$	4,057		2
	Corporate bonds		2,153		(3	)		2,150		1,879		(27	)		1,852		2
	Certificates of deposit		14,944		(14	)		14,930		0		0			0		2
		$	20,940	$	(10	)	$	20,930	$	5,953	$	(44	)	$	5,909
Summary of Restricted Marketable Securities Component and Workers' Compensation Deposits	The Company’s restricted marketable securities component of restricted marketable securities and workers’ compensation deposits consists of the following (in thousands):
		December 31, 2014							December 31, 2013							Fair
																Value
		Cost		Gross			Recorded		Cost		Gross			Recorded		Category
				Unrealized			Basis				Unrealized			Basis
				Gains							Gains
				(Losses)
	Current:
	Available-for-sale:
	Money market funds held in trust	$	3,776	$	0		$	3,776	$	0	$	0		$	0		2
		$	3,776	$	0		$	3,776	$	0	$	0		$	0
	Long term:
	Available-for-sale:
	Money market funds held in trust	$	46,310	$	0		$	46,310	$	0	$	0		$	0		2
	Municipal bonds		4,352		21			4,373		4,742		10			4,752		2
	Corporate bonds		3,540		(3	)		3,537		2,849		5			2,854		2
	U.S. treasuries		3,963		0			3,963		2,787		0			2,787		1
		$	58,165	$	18		$	58,183	$	10,378	$	15		$	10,393
Schedule of Long Term Restricted Certificates of Deposit	The Company’s long term restricted certificates of deposit are summarized as follows (in thousands):
		December 31, 2014							December 31, 2013
		Cost		Gross			Recorded		Cost		Gross			Recorded		Fair
				Unrealized			Basis				Unrealized			Basis		Value
				Gains							Gains					Category
	Restricted certificates of deposit	$	114,335	$	0		$	114,335	$	12,789	$	0		$	12,789		2

Property_Equipment_and_Softwar1

Property, Equipment and Software (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Summary of Property, Equipment and Software	Property, equipment and software consist of the following (in thousands):
		December 31,
		2014			2013
	Buildings	$	13,004		$	11,158
	Office furniture and fixtures		6,706			5,548
	Computer hardware and software		12,949			11,396
	Aircraft		4,668			4,617
			37,327			32,719
	Less accumulated depreciation and amortization		(16,142	)		(13,660	)
			21,185			19,059
	Land		1,490			1,490
		$	22,675		$	20,549

Workers_Compensation_Claims_Ta

Workers' Compensation Claims (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Summarizes Aggregate Workers' Compensation Reserve Activity	The following table summarizes the aggregate workers’ compensation reserve activity (in thousands):
		Year Ended December 31,
		2014		2013		2012
	Balance at January 1,
	Workers’ compensation claims liabilities	$	112,444	$	70,564	$	51,193
	Claims expense accrual:
	Current year		97,883		63,822		38,386
	Prior years		67,101		23,445		12,344
			164,984		87,267		50,730
	Claims payments related to:
	Current year		13,183		10,586		6,746
	Prior years		48,263		34,801		24,613
			61,446		45,387		31,359
	Balance at December 31,
	Workers’ compensation claims liabilities	$	215,982	$	112,444	$	70,564
	Incurred but not reported (IBNR)	$	113,984	$	69,611	$	47,992

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Summary of Minimum Annual Payments in Operating Lease Agreements	We lease office space for our branch offices under operating lease agreements that require minimum annual payments as follows (in thousands):
	Year ending
	December 31,
	2015	$	3,502
	2016		2,874
	2017		2,233
	2018		1,349
	2019		666
	2020		60
	Thereafter		0
		$	10,684

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Summary of Provision for Income Taxes from Continuing Operations	The provision for income taxes from continuing operations is as follows (in thousands):
		Year ended December 31,
		2014			2013			2012
	Current:
	Federal	$	(8,022	)	$	6,386		$	5,378
	State		(741	)		1,225			685
			(8,763	)		7,611			6,063
	Deferred:
	Federal		(10,237	)		(519	)		341
	State		747			(82	)		(76	)
			(9,490	)		(601	)		265
	Total (benefit) provision	$	(18,253	)	$	7,010		$	6,328
Summary of Deferred Income Tax Assets and Liabilities	Deferred income tax assets and liabilities are comprised of the following components (in thousands):
		December 31,
		2014			2013
	Gross deferred income tax assets:
	Workers’ compensation claims liabilities	$	12,168		$	6,985
	Safety incentives payable		3,782			3,529
	Allowance for doubtful accounts		118			94
	Tax effect of unrealized losses, net		856			959
	Alternative minimum tax credit carryforward		1,840			0
	State credit carryforward		969			805
	State loss carryforward		568			0
	Workers’ opportunity tax credit and EZ credit carryforward		3,162			0
	Other		605			504
			24,068			12,876
	Less valuation allowance		1,078			1,763
			22,990			11,113
	Gross deferred income tax liabilities:
	Tax depreciation in excess of book depreciation		(3,770	)		(2,793	)
	Tax amortization of goodwill		(11,588	)		(10,178	)
			(15,358	)		(12,971	)
	Net deferred income tax assets (liabilities)	$	7,632		$	(1,858	)
Summary of Effective Tax Rate for Continuing Operations Differed from U.S. Statutory Federal Tax Rate	The effective tax rate for continuing operations differed from the U.S. statutory federal tax rate due to the following:
		Year ended December 31,
		2014			2013			2012
	Statutory federal tax rate		(35.0	)%		35	%		35	%
	State taxes, net of federal benefit		0.2			3.4			0.4
	Valuation allowance on capital loss carryforward and state tax credit carryforward		(.2	)		(.4	)		2.3
	Adjustment for final positions on filed returns		(.7	)		(1.5	)		(.3	)
	Nondeductible expenses and other, net		2.2			0.8			4.4
	Federal tax-exempt interest income		(.2	)		(.2	)		(.4	)
	Federal and state tax credits		(6.6	)		(8.9	)		(8.9	)
			(40.3	)%		28.2	%		32.5	%

Stock_Incentive_Plans_Tables

Stock Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Options Activity	A summary of the status of the Company’s stock options at December 31, 2014, 2013 and 2012, together with changes during the periods then ended, is presented below:
		Number			Weighted
		of			average
		options			exercise
					price
	Outstanding at December 31, 2011		671,294
	Options granted at market price		7,500			17.55
	Options exercised		(131,997	)		13.98
	Options cancelled		(8,100	)		13.85
	Outstanding at December 31, 2012		538,697
	Options exercised		(138,298	)		13.53
	Outstanding at December 31, 2013		400,399
	Options exercised		(32,866	)		13.24
	Outstanding at December 31, 2014		367,533
	Available for grant at December 31, 2014		481,999
Summary of Stock Options Exercised and Outstanding	The following tables presents information on stock options exercised and outstanding:
		Year Ended
		December 31,
	(in thousands, except share data)	2014			2013
	Intrinsic value of options exercised in the period	$	1,025		$	6,089
	($ in thousands, except share data)	Number			Weighted		Weighted				Aggregate
		of			Average		Average				Intrinsic
		Shares			Exercise		Remaining				Value
					Price		Contractual
							Term (Years)
	Stock options:
	Outstanding December 31, 2014		367,533		$	15.22		5.25			$	4,478
	Exercisable at December 31, 2014		221,059			14.45		4.55				2,847
Summary of Fair Value of Stock Option Awards	The fair value of stock option awards as determined under the Black-Scholes option-pricing model was estimated with the following weighted-average assumptions:
		2012
	Expected volatility		65.9	%
	Risk free interest rate		2.9	%
	Expected dividend yield		2.5	%
	Expected term		7.3 years
	Weighted average fair value per share	$	9.08
Schedule of Restricted Stock Unit Activity	The following table presents restricted stock unit activity:
		Units			Weighted Average
					Grant Date
					Fair Value
	Non-vested at December 31, 2011		0		$	0
	Granted		47,500			21.44
	Non-vested at December 31, 2012		47,500			21.44
	Granted		44,970			50.28
	Vested		(10,302	)		21.44
	Cancelled/Forfeited		(1,573	)		21.44
	Non-vested at December 31, 2013		80,595			37.53
	Granted		69,371			50.47
	Vested		(15,253	)		33.4
	Cancelled/Forfeited		(7,867	)		34.9
	Non-vested at December 31, 2014		126,846			44.99
Summary of Stock-Based Compensation Expense Related to Stock Option and Restricted Stock Unit Awards	The following table summarizes stock-based compensation expense related to stock option and restricted stock unit awards (in thousands):
		Year Ended
		December 31,
		2014			2013		2012
	Stock-based compensation expense included in selling, general and administrative expenses	$	1,699		$	1,016	$	695
	Deferred income taxes		675			404		272
	Stock-based compensation expense related to stock options and restricted stock units, net of tax	$	1,024		$	612	$	423
Summary of Information about Stock Options Outstanding	The following table summarizes information about stock options outstanding at December 31, 2014:
	Options outstanding								Options exercisable
	Exercise price range	Number			Weighted-		Weighted-		Exercisable				Weighted-
		of			average		average		at				average
		shares			exercise		remaining		December 31,				exercise
					price		contractual		2014				price
							life (years)
	$2.01 - $  2.58		2,250		$	2.29	Indefinite			2,250			$	2.29
	8.82 -  17.55		365,283			15.29	5.3			218,809				14.57
			367,533			15.22				221,059				14.45

Quarterly_Financial_Informatio1

Quarterly Financial Information (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Financial Information
		First			Second		Third			Fourth
		Quarter			Quarter		Quarter			Quarter
	Year ended December 31, 2014
	Revenues	$	135,140		$	151,069	$	174,959		$	175,016
	Cost of revenues		125,834			121,217		217,741			140,975
	Net (loss) income		(3,583	)		7,283		(37,818	)		7,034
	Basic (loss) earnings per share		(0.50	)		1.02		(5.27	)		0.99
	Diluted (loss) earnings per share		(0.50	)		0.98		(5.27	)		0.97
	Common stock market prices:
	High		102.2			63.19		63.45			45.38
	Low		57.82			41.96		39.47			18.25
	Year ended December 31, 2013
	Revenues	$	111,551		$	128,798	$	147,971		$	144,524
	Cost of revenues		103,240			105,072		117,785			120,223
	Net (loss) income		(2,549	)		5,886		8,994			5,561
	Basic (loss) earnings per share		(0.36	)		0.83		1.26			0.78
	Diluted (loss) earnings per share		(0.36	)		0.8		1.21			0.74
	Common stock market prices:
	High		53.27			62.82		73.49			98
	Low		38.15			48.5		48.08			66.33

Summary_of_Operations_and_Sign3

Summary of Operations and Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 01, 2010
	Segment
	Unit
Basis Of Presentation Of Interim Period Statements [Line Items]
Restricted capital	$58,533,000	$11,205,000
Operating and reporting segment	1
Revenue recognition professional employer services contracts term	1 year
Professional employer service contract cancellation and termination period	30 days
Cash and cash equivalents, maturity term	3 months
Number of reporting unit	1
Goodwill and intangible assets impairment	0
Income taxes paid	3,300,000	9,000,000	3,300,000
Anti-dilutive common shares excluded from calculation of diluted loss per share	227,000
California [Member]
Basis Of Presentation Of Interim Period Statements [Line Items]
Revenue from attributable to geographic area	77.00%	74.00%	69.00%
Ecole Insurance Company [Member]
Basis Of Presentation Of Interim Period Statements [Line Items]
Restricted capital				6,100,000
Minimum [Member]
Basis Of Presentation Of Interim Period Statements [Line Items]
Restricted marketable securities maturity period	180 days	180 days
Likelihood of tax benefit being realized upon settlement	50.00%
Minimum [Member] | AICE [Member]
Basis Of Presentation Of Interim Period Statements [Line Items]
Workers Compensation Coverage Per Occurrence	1,000,000
Maximum [Member]
Basis Of Presentation Of Interim Period Statements [Line Items]
Restricted marketable securities maturity period	2 years	2 years
Maximum [Member] | AICE [Member]
Basis Of Presentation Of Interim Period Statements [Line Items]
Workers Compensation Coverage Per Occurrence	$5,000,000

Summary_of_Operations_and_Sign4

Summary of Operations and Significant Accounting Policies - Summary of Allowance for Doubtful Accounts (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Receivables [Abstract]
Allowance for doubtful accounts, beginning balance	$242	$381	$452
Charges to expense	103	300	195
Write-offs of uncollectible accounts, net of recoveries	-54	-439	-266
Allowance for doubtful accounts, ending balance	$291	$242	$381

Summary_of_Operations_and_Sign5

Summary of Operations and Significant Accounting Policies - Summary of Property, Equipment and Software Over Estimated Useful Life (Detail)	12 Months Ended
	Dec. 31, 2014
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	39 years
Office Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	7 years
Aircraft [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	20 years
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Leasehold improvements	Shorter of lease term or estimated useful life
Minimum [Member] | Computer Hardware and Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member] | Computer Hardware and Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years

Summary_of_Operations_and_Sign6

Summary of Operations and Significant Accounting Policies - Summary of Basic and Diluted Common Shares Outstanding (Detail)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Weighted average number of basic shares outstanding	7,160	7,105	7,723
Effect of dilutive securities	0	292	140
Weighted average number of diluted shares outstanding	7,160	7,397	7,863

Stock_Repurchase_Additional_In

Stock Repurchase - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended			0 Months Ended
	Sep. 28, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 28, 2012	Sep. 21, 2012
Equity, Class of Treasury Stock [Line Items]
Repurchase common stock held by promoter, one		87,200	0	0
Repurchase share price, per share		$0.01	$0.01		20
Total consideration					59,700,000
Stock repurchase in cash		3,676,000	0	25,432,000
Non-Voting Redeemable Preferred Stock with a liquidation preference		$1,000
Professional and legal fees		514,000
Redemption of outstanding shares of Series A Nonconvertible, Non-Voting Redeemable Preferred Stock						34,800,000
Decrease in dividend obligation after redemption of preferred stock	870,000
Dividend rate on preferred stock paid semi-annually	5.00%
Preferred stock redemption period		6 months
Series A Nonconvertible, Non-Voting Redeemable Preferred Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchase from issued shares		34,800
Promoter One [Member]
Equity, Class of Treasury Stock [Line Items]
Repurchase common stock held by promoter, one					2,485,929
Promoter Two [Member]
Equity, Class of Treasury Stock [Line Items]
Repurchase common stock held by promoter, one					500,000
Cash [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchase in cash		$24,900,000

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments and Concentration of Credit Risk - Additional Information (Detail) (Credit Concentration Risk [Member], USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Certificate of Deposits [Member]
Concentration Risk [Line Items]
Marketable securities	$137.60
Money Market Funds Held in Trust [Member]
Concentration Risk [Line Items]
Marketable securities	50.1
Variable Rate Demand Notes (VRDN) [Member]
Concentration Risk [Line Items]
Marketable securities	21.7
Municipal Bonds [Member]
Concentration Risk [Line Items]
Marketable securities	8.2
Corporate Bonds [Member]
Concentration Risk [Line Items]
Marketable securities	$5.70

Fair_Value_Measurement_Additio

Fair Value Measurement - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
	Investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of investment brokers	3
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of assets held by entity under fair value	0
Number of liabilities held by entity under fair value	0

Fair_Value_Measurement_Summary

Fair Value Measurement - Summary of Marketable Securities Consist of Investments (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Recorded Basis	$20,930	$5,909
Recorded Basis	29,957	19,787
Current Available-for-Sale [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	30,000	19,800
Gross Unrealized Gains (Losses)	-43	-13
Recorded Basis	29,957	19,787
Long-Term Available-for-Sale [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	20,940	5,953
Gross Unrealized Gains (Losses)	-10	-44
Recorded Basis	20,930	5,909
Municipal Bonds [Member] | Long-Term Available-for-Sale [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	3,843	4,074
Gross Unrealized Gains (Losses)	7	-17
Recorded Basis	3,850	4,057
Corporate Bonds [Member] | Current Available-for-Sale [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	0	9,800
Gross Unrealized Gains (Losses)	0	-13
Recorded Basis	0	9,787
Corporate Bonds [Member] | Long-Term Available-for-Sale [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	2,153	1,879
Gross Unrealized Gains (Losses)	-3	-27
Recorded Basis	2,150	1,852
Variable Rate Demand Notes (VRDN) [Member] | Current Available-for-Sale [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	21,670	10,000
Gross Unrealized Gains (Losses)	0	0
Recorded Basis	21,670	10,000
Certificate of Deposits [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	14,944	0
Gross Unrealized Gains (Losses)	-14	0
Recorded Basis	14,930	0
Certificate of Deposits [Member] | Current Available-for-Sale [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	8,330	0
Gross Unrealized Gains (Losses)	-43	0
Recorded Basis	$8,287	$0

Fair_Value_Measurement_Summary1

Fair Value Measurement - Summary of Restricted Marketable Securities Component and Workers' Compensation Deposits (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Long-Term Available-for-Sale [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	$20,940	$5,953
Long-Term Available-for-Sale [Member] | Municipal Bonds [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	3,843	4,074
Long-Term Available-for-Sale [Member] | Corporate Bonds [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	2,153	1,879
Restricted Marketable Securities [Member] | Long-Term Available-for-Sale [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	58,165	10,378
Gross Unrealized Gains (Losses)	18	15
Recorded Basis	58,183	10,393
Restricted Marketable Securities [Member] | Long-Term Available-for-Sale [Member] | Money Market Funds Held in Trust [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	46,310	0
Gross Unrealized Gains (Losses)	0	0
Recorded Basis	46,310	0
Restricted Marketable Securities [Member] | Long-Term Available-for-Sale [Member] | Municipal Bonds [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	4,352	4,742
Gross Unrealized Gains (Losses)	21	10
Recorded Basis	4,373	4,752
Restricted Marketable Securities [Member] | Long-Term Available-for-Sale [Member] | Corporate Bonds [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	3,540	2,849
Gross Unrealized Gains (Losses)	-3	5
Recorded Basis	3,537	2,854
Restricted Marketable Securities [Member] | Long-Term Available-for-Sale [Member] | U.S. Treasuries [Member] | Level 1 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	3,963	2,787
Gross Unrealized Gains (Losses)	0	0
Recorded Basis	3,963	2,787
Restricted Marketable Securities [Member] | Current Available-for-Sale [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	3,776	0
Gross Unrealized Gains (Losses)	0	0
Recorded Basis	3,776	0
Restricted Marketable Securities [Member] | Current Available-for-Sale [Member] | Money Market Funds Held in Trust [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	3,776	0
Gross Unrealized Gains (Losses)	0	0
Recorded Basis	$3,776	$0

Fair_Value_Measurement_Schedul

Fair Value Measurement - Schedule of Long-Term Restricted Certificates of Deposit (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	$114,335	$12,789
Restricted Certificates of Deposit [Member] | Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost	114,335	12,789
Gross Unrealized Gains	0	0
Recorded Basis	$114,335	$12,789

Property_Equipment_and_Softwar2

Property, Equipment and Software - Summary of Property, Equipment and Software (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	$37,327	$32,719
Less accumulated depreciation and amortization	-16,142	-13,660
Property, Plant and Equipment, Gross	21,185	19,059
Land	1,490	1,490
Property, Plant and Equipment, Net	22,675	20,549
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	13,004	11,158
Office Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	6,706	5,548
Computer Hardware and Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	12,949	11,396
Aircraft [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	$4,668	$4,617

Workers_Compensation_Claims_Ad

Workers' Compensation Claims - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2014	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated future liability for unsettled workers' compensation		$215,982,000	$112,444,000	$70,564,000		$51,193,000
Total workers' compensation claims expense	101,200,000	164,984,000	87,267,000	50,730,000
Change in estimate workers' compensation claims expense relating to prior period	61,300,000	67,101,000	23,445,000	12,344,000
Receivable from insurer for insured claims liability		781,000	768,000
Long-term workers' compensation claims liabilities		271,000
Aggregate undiscounted payout amount		360,000
Balance in trust account		50,100,000			20,000,000
Specified investment balances or other financial instruments		198,500,000	72,900,000
Letter of credit		114,300,000
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Discount rates applied to discounted liabilities		4.25%
Pay-out periods to the beneficiaries		7 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Discount rates applied to discounted liabilities		9.00%
Pay-out periods to the beneficiaries		32 years
California [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Surety bonds and standby letters of credit		194,900,000
Increasing Company's surety deposit requirement		190,600,000
ACE Group [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess workers' compensation insurance coverage with ACE group		5,000,000
ACE Group [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess workers' compensation insurance coverage with ACE group		15,000,000
ACE Group [Member] | Colorado [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess workers' compensation insurance coverage with American Insurance Company		Statutory limits
ACE Group [Member] | Colorado [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess workers' compensation insurance coverage with ACE group		2,000,000
ACE Group [Member] | Maryland [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess workers' compensation insurance coverage with ACE group		1,000,000
ACE Group [Member] | Maryland [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess workers' compensation insurance coverage with ACE group		25,000,000
Wells Fargo [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Certificates of deposit posted as collateral		114,300,000
AICE [Member] | Self-Insured States [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess workers' compensation insurance retention		5,000,000
AICE [Member] | Colorado [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess workers' compensation insurance retention		2,000,000
AICE [Member] | Maryland [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess workers' compensation insurance retention		1,000,000
Barrett Business Services Inc [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Worker's compensation risk claim		5,000,000
Worker's compensation risk claim maximum		$5,000,000

Workers_Compensation_Claims_Su

Workers' Compensation Claims - Summarizes Aggregate Workers' Compensation Reserve Activity (Detail) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Workers Compensation Reserve [Abstract]
Workers' compensation claims liabilities, Beginning balance		$112,444	$70,564	$51,193
Claims expense accrual:
Current year		97,883	63,822	38,386
Prior years	61,300	67,101	23,445	12,344
Total expense accrual	101,200	164,984	87,267	50,730
Claims payments related to:
Current year		13,183	10,586	6,746
Prior years		48,263	34,801	24,613
Total paid		61,446	45,387	31,359
Workers' compensation claims liabilities, Ending balance		215,982	112,444	70,564
Incurred but not reported (IBNR)		$113,984	$69,611	$47,992

Revolving_Credit_Facility_and_1

Revolving Credit Facility and Long-Term Debt - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 29, 2014
Line of Credit Facility [Line Items]
Line of credit facility commitment fee description	The Agreement also provides for an unused commitment fee of 0.35% per year on the average dailyunused amount of the revolving credit facility, and a fee of 1.75% of the face amount of each letter of credit
Ratio of restricted and unrestricted cash and marketable securities to workers' compensation and safety incentive liabilities	1
Maximum amount of capital expenditures in 2015	5,000,000
Maximum amount of capital expenditures in 2016	4,000,000
Wells Fargo [Member]
Line of Credit Facility [Line Items]
Term loan payment due June 30, 2015	3,000,000
Term loan payment due September 30, 2015	7,000,000
Term loan payment due December 31, 2015	15,000,000
Term loan payment due June 30, 2016	5,000,000
Term loan payment due September 30, 2016	5,000,000
Minimum [Member]
Line of Credit Facility [Line Items]
Minimum Fixed Charge Coverage Ratio	1.5
Prohibition on incurring additional indebtedness without the prior approval of the Bank in purchase money financing	200,000
Maximum [Member]
Line of Credit Facility [Line Items]
Prohibition on incurring additional indebtedness without the prior approval of the Bank in purchase money financing	400,000
Cash dividend	0.22
Term Loan [Member]
Line of Credit Facility [Line Items]
Term loan from Bank, Interest rate description	One month LIBOR plus 2.25%
LIBOR plus rate	2.25%
Term loan with principal bank	5,100,000
Payment of monthly installments of term loan	18,375
Term Loan [Member] | Wells Fargo [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity		40,000,000
Term loan maturity date	31-Dec-16
Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member] | Wells Fargo [Member]
Line of Credit Facility [Line Items]
Term loan from Bank, Interest rate description	One month LIBOR plus 4.0%
LIBOR plus rate	4.00%
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Outstanding borrowings on the revolving credit facility	0
Unused commitment fee on unused amount	0.35%
Revolving Credit Facility [Member] | Wells Fargo [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity		14,000,000
Revolving Credit Facility [Member] | Daily Floating Rate [Member]
Line of Credit Facility [Line Items]
Term loan from Bank, Interest rate description	A daily floating rate of one month LIBOR plus 2%
LIBOR plus rate	2.00%
Revolving Credit Facility [Member] | Fixed Rate [Member]
Line of Credit Facility [Line Items]
Term loan from Bank, Interest rate description	A fixed rate of LIBOR plus 2.0%
LIBOR plus rate	2.00%
Standby Letters of Credit [Member] | Wells Fargo [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity		5,000,000
Cash-Secured Letters of Credit [Member]
Line of Credit Facility [Line Items]
Unused commitment fee on unused amount	175.00%
Cash-Secured Letters of Credit [Member] | Wells Fargo [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity		114,300,000
Cash-Secured Letters of Credit [Member] | Wells Fargo [Member] | Certificate of Deposits [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity	114,300,000
Credit facility non-refundable commitment fee	400,000

401k_Savings_Plan_Additional_I

401(k) Savings Plan - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Age
	H
Compensation and Retirement Disclosure [Abstract]
Age to participate in the savings plan	21
Time to participate in the savings plan	1,000
Consecutive period to participate in the savings plan	12 months
Discretionary Company contributions	$0	$0	$0
Contributions by management	100.00%
Percentage of each participating employee annual compensation	3.00%
Employee's contributions	50.00%
Additional annual compensation	2.00%
Matching contributions	$885,000	$734,000	$610,000

Commitments_and_Contingencies_1

Commitments and Contingencies - Summary of Minimum Annual Payments in Operating Lease Agreements (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Leases [Abstract]
2015	$3,502
2016	2,874
2017	2,233
2018	1,349
2019	666
2020	60
Thereafter	0
Total	$10,684

Commitments_and_Contingencies_2

Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Leases [Abstract]
Rent expense	$3.70	$3.20	$2.80

Income_Taxes_Summary_of_Provis

Income Taxes - Summary of Provision for Income Taxes from Continuing Operations (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current:
Federal	($8,022)	$6,386	$5,378
State	-741	1,225	685
Current income tax expense	-8,763	7,611	6,063
Deferred:
Federal	-10,237	-519	341
State	747	-82	-76
Deferred income taxes	-9,490	-601	265
Total (benefit) provision for income taxes	($18,253)	$7,010	$6,328

Income_Taxes_Summary_of_Deferr

Income Taxes - Summary of Deferred Income Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Gross deferred income tax assets:
Workers' compensation claims liabilities	$12,168	$6,985
Safety incentives payable	3,782	3,529
Allowance for doubtful accounts	118	94
Tax effect of unrealized losses, net	856	959
Alternative minimum tax credit carryforward	1,840	0
State credit carryforward	969	805
State loss carryforward	568	0
Workers' opportunity tax credit and EZ credit carryforward	3,162	0
Other	605	504
Deferred tax assets, gross total	24,068	12,876
Less valuation allowance	1,078	1,763
Deferred tax assets, net total	22,990	11,113
Gross deferred income tax liabilities:
Tax depreciation in excess of book depreciation	-3,770	-2,793
Tax amortization of goodwill	-11,588	-10,178
Deferred Tax Liabilities, gross total	-15,358	-12,971
Net deferred income tax assets (liabilities)	$7,632	($1,858)

Income_Taxes_Summary_of_Effect

Income Taxes - Summary of Effective Tax Rate for Continuing Operations Differed from U.S. Statutory Federal Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Statutory federal tax rate	-35.00%	35.00%	35.00%
State taxes, net of federal benefit	0.20%	3.40%	0.40%
Valuation allowance on capital loss carryforward and state tax credit carryforward	-0.20%	-0.40%	2.30%
Adjustment for final positions on filed returns	-0.70%	-1.50%	-0.30%
Nondeductible expenses and other, net	2.20%	0.80%	4.40%
Federal tax-exempt interest income	-0.20%	-0.20%	-0.40%
Federal and state tax credits	-6.60%	-8.90%	-8.90%
Total	-40.30%	28.20%	32.50%

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Line Items]
Valuation allowance of federal and state tax benefits not expected to be utilized	$1,078,000	$1,763,000
Additional valuation allowance	0
Unrecognized tax benefits	0	0
Reduction in state tax benefit	4,000	284,000	498,000
State [Member]
Income Tax Disclosure [Line Items]
Tax credit carry forwards	1,500,000
Tax credit carry forwards expiration date	31-Dec-24
California [Member]
Income Tax Disclosure [Line Items]
Operating loss carry forwards	6,700,000
Operating loss carry forwards expiration date	31-Dec-34
Other States [Member]
Income Tax Disclosure [Line Items]
Operating loss carry forwards	3,900,000
Capital Loss Carry Forward [Member]
Income Tax Disclosure [Line Items]
Tax credit carry forwards	2,100,000
Tax credit carry forwards expiration date	31-Dec-15
Federal General Business Tax Credit Carry Forward [Member]
Income Tax Disclosure [Line Items]
Tax credit carry forwards	3,200,000
Tax credit carry forwards expiration date	31-Dec-24
Alternative Minimum Tax Credit Carry Forward [Member]
Income Tax Disclosure [Line Items]
Tax credit carry forwards	$1,800,000
Minimum [Member] | Other States [Member]
Income Tax Disclosure [Line Items]
Operating loss carry forwards expiration date	31-Dec-21
Maximum [Member] | Other States [Member]
Income Tax Disclosure [Line Items]
Operating loss carry forwards expiration date	31-Dec-34

Stock_Incentive_Plans_Addition

Stock Incentive Plans - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	Installment	Installment	Installment
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based awards issued to outside consultants or advisors	0
Number of shares of common stock reserved for issuance under the 2009 Plan	1,000,000
Aggregate number of shares for which incentive stock options may be granted under the Plan	900,000
Option awards shares outstanding under the 2009 plan together with the 2003 Plan and its predecessor	367,533	400,399	538,697	671,294
Outstanding options expiration period from the date of grant	10 years
Number of equal annual installments options are exercisable	4
Options exercisable period after date of grant	1 year
New grants of stock options	0	44,970	47,500
Restricted stock units outstanding	126,846
Options granted	0	0	0
Weighted average grant date fair value of restricted stock units, granted	$50.47	$50.28	$21.44
Number of equal annual installments in which restricted stock units vest	4	4	4
Annual installments for vesting of restricted stock beginning from date of grant, period	1 year	1 year	1 year
Unrecognized compensation expense related to stock options	$5.60
Weighted average period	3 years 1 month 24 days

Stock_Incentive_Plans_Summary_

Stock Incentive Plans - Summary of Stock Options Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding beginning balance, Number of options	400,399	538,697	671,294
Options granted, Number of options			7,500
Options exercised, Number of options	-32,866	-138,298	-131,997
Options cancelled, Number of options			-8,100
Outstanding ending balance, Number of options	367,533	400,399	538,697
Options granted, Weighted average exercise price			$17.55
Available for grant, Number of options	481,999
Options exercised, Weighted average exercise price	$13.24	$13.53	$13.98
Options cancelled , Weighted average exercise price			$13.85

Stock_Incentive_Plans_Summary_1

Stock Incentive Plans - Summary of Stock Options Exercised and Outstanding (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Intrinsic value of options exercised in the period	$1,025	$6,089
Stock options:
Number of options, outstanding stock options	367,533	400,399	538,697	671,294
Number of options, exercisable stock options	221,059
Weighted average exercise price, outstanding stock option	$15.22
Weighted average exercise price, exercisable stock options	$14.45
Weighted average contractual term of outstanding stock options	5 years 3 months
Weighted average contractual term of exercisable stock options	4 years 6 months 18 days
Aggregate intrinsic value, outstanding stock option	4,478
Aggregate intrinsic value, exercisable stock option	$2,847

Stock_Incentive_Plans_Summary_2

Stock Incentive Plans - Summary of Fair Value of Stock Option Awards (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected volatility	65.90%
Risk free interest rate	2.90%
Expected dividend yield	2.50%
Expected term	7 years 3 months 18 days
Weighted average fair value per share	$9.08

Stock_Incentive_Plans_Schedule

Stock Incentive Plans - Schedule of Restricted Stock Unit Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Units	0	44,970	47,500
Non-vested ending balance, Units	126,846
Granted, Weighted Average Grant Date Fair Value	$50.47	$50.28	$21.44
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested beginning balance, Units	80,595	47,500	0
Granted, Units	69,371	44,970	47,500
Vested, Units	-15,253	-10,302
Cancelled/Forfeited, Units	-7,867	-1,573
Non-vested ending balance, Units	126,846	80,595	47,500
Non-vested, Weighted Average Grant Date Fair Value at Beginning balance	$37.53	$21.44	$0
Granted, Weighted Average Grant Date Fair Value	$50.47	$50.28	$21.44
Vested, Weighted Average Grant Date Fair Value	$33.40	$21.44
Cancelled/Forfeited, Weighted Average Grant Date Fair Value	$34.90	$21.44
Non-vested, Weighted Average Grant Date Fair Value at Ending balance	$44.99	$37.53	$21.44

Stock_Incentive_Plans_Summary_3

Stock Incentive Plans - Summary of Stock-Based Compensation Expense Related to Stock Option and Restricted Stock Unit Awards (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Service Share-based Compensation, Aggregate Disclosures [Abstract]
Stock-based compensation expense included in selling, general and administrative expenses	$1,699	$1,016	$695
Deferred income taxes	675	404	272
Stock-based compensation expense related to stock options and restricted stock units, net of tax	$1,024	$612	$423

Stock_Incentive_Plans_Summary_4

Stock Incentive Plans - Summary of Information about Stock Options Outstanding (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Number of shares	367,533
Option outstanding, Weighted-average exercise price	$15.22
Options exercisable, Exercisable at December 31, 2014	221,059
Options exercisable, Weighted-average exercise price	$14.45
Range One [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Number of shares	2,250
Option outstanding, Weighted-average exercise price	$2.29
Option outstanding, Weighted-average remaining contractual life	Indefinite
Options exercisable, Exercisable at December 31, 2014	2,250
Options exercisable, Weighted-average exercise price	$2.29
Option outstanding, Exercise price range, Lower range limit	$2.01
Option outstanding, Exercise price range, Upper range limit	$2.58
Range Two [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Number of shares	365,283
Option outstanding, Weighted-average exercise price	$15.29
Option outstanding, Weighted-average remaining contractual life (year)	5 years 3 months 18 days
Options exercisable, Exercisable at December 31, 2014	218,809
Options exercisable, Weighted-average exercise price	$14.57
Option outstanding, Exercise price range, Lower range limit	$8.82
Option outstanding, Exercise price range, Upper range limit	$17.55

Stock_Repurchase_Program_Addit

Stock Repurchase Program - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity [Abstract]
Cost of repurchase	1,100,000
Repurchased shares	87,200	0	0
Weighted average price	$42.16

Quarterly_Financial_Informatio2

Quarterly Financial Information - Summary of Quarterly Financial Information (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Revenues	$175,016	$174,959	$151,069	$135,140	$144,524	$147,971	$128,798	$111,551	$636,184	$532,844	$402,652
Cost of revenues	140,975	217,741	121,217	125,834	120,223	117,785	105,072	103,240	605,767	446,320	335,938
Net (loss) income	$7,034	($37,818)	$7,283	($3,583)	$5,561	$8,994	$5,886	($2,549)	($27,084)	$17,892	$13,131
Basic (loss) earnings per share	$0.99	($5.27)	$1.02	($0.50)	$0.78	$1.26	$0.83	($0.36)	($3.78)	$2.52	$1.70
Diluted (loss) earnings per share	$0.97	($5.27)	$0.98	($0.50)	$0.74	$1.21	$0.80	($0.36)	($3.78)	$2.42	$1.67
Common stock market prices:
High	$45.38	$63.45	$63.19	$102.20	$98	$73.49	$62.82	$53.27
Low	$18.25	$39.47	$41.96	$57.82	$66.33	$48.08	$48.50	$38.15